CriticalCVE-2026-96655

    Plex Media Server arbitrary-host SSRF (CVE-2026-96655)

    Published Last modified In CISA KEV since Sources: pwn.watch, CVE.org

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    What is affected, what to do

    Plex Media Server before 1.43.3.10861 allows an authenticated user to request arbitrary internal or external addresses via the '/video/:/transcode/universal' path parameter.

    The vulnerability is being actively exploited; treat it as a priority. Update Plex Media Server to version 1.43.3.10861. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Plex Media Server lt *..1.43.3.10861
    Fixed in
    • Plex Media Server 1.43.3.10861

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    5.3

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v4

    4.3

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: pwn.watch, CVE.org

    10.7 %

    EPSS score

    Elevated — model estimates 10-50% exploitation likelihood.

    Source: FIRST EPSS, percentile 95.9

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    226.94 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: VulnCheck KEV (opens in a new tab) How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    5.3 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    4.3
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    5.3
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    10.7 %
    Elevated — model estimates 10-50% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    95.9
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 20 October 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-918

    Response and mitigation

    Why act now?

    Prioritisation rationale

    On its own this is a modest-severity flaw. It is network-reachable but needs a low-privileged account and only affects confidentiality. The predictive exploitation model rates its likelihood as fairly low, and CISA does not flag known ransomware use. Its KEV listing is best explained by the documented chaining with CVE-2026-96652, CVE-2026-96654 and CVE-2026-96656, where the SSRF becomes a pivot into internal networks or cloud metadata services. Typical targets are internet-exposed Plex instances on NAS boxes, homelabs and home-office machines of technical staff who also hold corporate VPN access. Treat it as high priority (patch within 72 h) wherever an instance is internet-facing or has a network path into corporate segments. Isolated instances without external users can follow the normal patch cycle. In KRITIS environments, Plex should generally be classed as unapproved software and removed.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory: Find every Plex Media Server instance, including shadow IT such as NAS appliances, Docker hosts, remote-worker machines with VPN access and lab VMs. Useful methods are a scan for the default Plex port 32400/TCP, an EDR query for Plex Media Server.exe/Plex Transcoder and a registry search for plexinc/pms-docker images.
      • Patch: Upgrade to Plex Media Server 1.43.3.10861 or later. The affected-product data also lists 1.43.0.10861 as a fixed build. Verify the exact fixed version in the Plex security advisory and move to the newest available build.
      • Cut exposure: For instances you cannot patch today, disable "Remote Access" in server settings, remove port forwards and UPnP/NAT-PMP mappings for 32400/TCP at the perimeter, and pause any reverse-proxy publication.
      • Review who can authenticate: Exploitation requires a valid account. Enumerate shared libraries, managed/home users and shares to external Plex accounts, then revoke anything unknown or no longer needed.
      • Token hygiene: If compromise is suspected, rotate the Plex account password and X-Plex-Token, sign out all authorised devices and enforce 2FA on the owner account.
      • Assess the chain: Check patch status for CVE-2026-96652, CVE-2026-96654 and CVE-2026-96656 in the same change, since CISA notes the SSRF can be chained with them.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Place Plex hosts in an isolated VLAN/DMZ. Allow outbound traffic only to the internet destinations needed for plex.tv and metadata. Deny egress to RFC1918 ranges, management VLANs, 127.0.0.0/8 and link-local 169.254.0.0/16 so the SSRF cannot reach internal services.
      • Cloud/container hardening: Enforce IMDSv2 on IaaS hosts (AWS: HttpTokens=required, hop limit 1). Alternatively, block 169.254.169.254 from the Plex container via iptables or a Kubernetes NetworkPolicy.
      • WAF/reverse proxy: Block or alert on requests to /video/:/transcode/universal whose query parameters (e.g. path=) carry absolute URLs (http://, https://, file://, gopher://), IP literals or internal hostnames. Legitimate transcode calls reference library paths such as /library/metadata/<id>.
      • Least privilege (IAM): Run Plex under a dedicated, unprivileged service account that is not domain-joined and has no access to admin shares. Never run it on admin workstations.
      • Configuration: Shrink "Allowed networks without auth" (allowedNetworks) to the minimum so LAN clients are not implicitly treated as authenticated.

    3. Runbook step 3

      Detection rules

      • Plex/proxy access logs: Look for transcode calls with embedded URLs. Example SPL: index=web uri_path="/video/:/transcode/universal*" (uri_query="*http%3A*" OR uri_query="*169.254*" OR uri_query="*127.0.0.1*" OR uri_query="*localhost*"). Local logs are in Plex Media Server/Logs/Plex Media Server.log.
      • Sysmon EID 3 / EDR network events: Watch for outbound connections from Plex Media Server.exe or Plex Transcoder.exe to internal addresses or 169.254.169.254. Example KQL: DeviceNetworkEvents | where InitiatingProcessFileName has "Plex" and (ipv4_is_private(RemoteIP) or RemoteIP=="169.254.169.254").
      • Zeek/Suricata: Check conn.log/http.log for traffic sourced from the Plex host toward management networks or admin ports (22, 445, 3389, 5985, 8080, 9200). A wide spread of destination ports from that single source suggests SSRF-driven internal port scanning.
      • Account anomalies: Watch for new shares or devices on the owner account, or shared-user logins from unusual geolocations. Treat these as higher risk when followed by bursts of transcode requests returning 4xx/5xx.
      • Sigma shape: logsource: webserver with selection: cs-uri-stem|contains: '/transcode/universal' and cs-uri-query|contains|all: ['path=', '://'], filter: cs-uri-query|contains: '/library/', condition: selection and not filter.

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    Plex Media Server before 1.43.3.10861 allows an authenticated user to request arbitrary internal or external addresses via the '/video/:/transcode/universal' path parameter.

    Source: pwn.watch, cvelistv5, NVD (NIST), CISA KEV Catalog

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    PlexMedia Server
    • < 1.43.3.10861
    • 1.43.3.10861
    plexmedia_server
    • < 1.43.3.10861
    • 1.43.3.10861

    Vendors and products

    Weakness classes (CWE)

    • CWE-918Server-Side Request Forgery (SSRF)

      Base

      The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

      Entry at MITRE CWE-918

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited

    References & sources

    • raw.githubusercontent.comurlThird-party advisory, Third-party advisory
    • forums.plex.tvurlRelease notes, Release notes
    • CVE.org (MITRE)urlVulnerability database, Third-party advisory, Vulnerability database
    • zmain.infourlThird-party advisory, Third-party advisory
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96655government-resource, US government resource
    • pwn.watchpwn.watch: Plex2Shell: chained Plex Media Server RCE exploited for minerspwn-watch
    • bleepingcomputer.comCISA / BleepingComputer: Plex2Shell actively exploitedpwn-watch
    • forums.plex.tvPlex forum: Important Security Updatepwn-watch
    • CVE.org (MITRE)CVE-2026-96652pwn-watch
    • qnap.comQNAP Security Notice: Plex Media Server Vulnerabilities (Plex2Shell) – Update to 1.43.3.10861 or Later Immediatelypwn-watch
    • bleepingcomputer.comQNAP says hackers breaching NAS devices in Plex2Shell attackspwn-watch

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. NVD analysis modifiedNVD

      Product mapping changed:
      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationchanged
      OR *cpe:2.3:a:plex:media_server:*:*:*:*:*:*:*:* versions up to (excluding) 1.43.0.10861
      OR *cpe:2.3:a:plex:media_server:*:*:*:*:*:*:*:* versions up to (excluding) 1.43.3.10861
      Reference typeadded
      —
      CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96655 Types: US Government Resource

      Source identifier: nvd@nist.gov

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: active, automatable: no

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentremoved
      {"id":"CVE-2026-96655","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-20T19:46:38.103247Z"}
      —
      SSVC assessmentadded
      —
      {"id":"CVE-2026-96655","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-20T00:00:00+00:00"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    3. CISA KEV entry updated9119a7d8…

      4 individual changes: Date Added, Due Date, Required Action, Vulnerability Name

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Date Addedadded
      —
      2026-10-20
      Due Dateadded
      —
      2026-10-20
      Required Actionadded
      —
      2026-10-20
      Vulnerability Nameadded
      —
      2026-10-20

      Source identifier: 9119a7d8-5eab-497f-8521-727c672e3725

    4. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: active, automatable: no

      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96655
      SSVC assessmentremoved
      {"id":"CVE-2026-96655","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-09-23T16:34:51.715177Z"}
      —
      SSVC assessmentadded
      —
      {"id":"CVE-2026-96655","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-20T19:46:38.103247Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    5. Initial analysis by NVDNVD

      Newly listed as affected:
      Show 5 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationadded
      —
      OR *cpe:2.3:a:plex:media_server:*:*:*:*:*:*:*:* versions up to (excluding) 1.43.0.10861
      Reference typeadded
      —
      Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government: https://forums.plex.tv/t/plex-media-server/30447/711 Types: Release Notes
      Reference typeadded
      —
      Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-01.json Types: Third Party Advisory
      Reference typeadded
      —
      Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government: https://www.cve.org/CVERecord?id=CVE-2026-96655 Types: Third Party Advisory, VDB Entry
      Reference typeadded
      —
      Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government: https://zmain.info/blog/plex2shell Types: Third Party Advisory

      Source identifier: nvd@nist.gov

    Show 2 older changes

    1. Received9119a7d8…

      CVSS V4.0: AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

      CVSS V3.1: AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Weakness type: CWE-918

      Description added or changed

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      Plex Media Server before 1.43.3.10861 allows an authenticated user to request arbitrary internal or external addresses via the '/video/:/transcode/universal' path parameter.
      CVSSadded
      —
      AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      CVSSadded
      —
      AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
      Weakness type (CWE)added
      —
      CWE-918
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96655.json">CVE-2026-96655</a>
      Referenceadded
      —
      https://forums.plex.tv/t/plex-media-server/30447/711
      Referenceadded
      —
      https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-01.json
      Referenceadded
      —
      https://www.cve.org/CVERecord?id=CVE-2026-96655
      Referenceadded
      —
      https://zmain.info/blog/plex2shell
      SSVC assessmentadded
      —
      {"id":"CVE-2026-96655","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-09-14T18:23:48.400949Z"}

      Source identifier: 9119a7d8-5eab-497f-8521-727c672e3725

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-96655","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-09-23T16:34:51.715177Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

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