CriticalCVE-2026-114713

    UnrealIRCd Improper Neutralization of Delimiters Vulnerability (CVE-2026-114713)

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

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    What is affected, what to do

    The labeled-response module in UnrealIRCd 6.0.0 before 6.2.7.1 does not escape the IRCv3 "label" message tag when echoing it into replies, which allows any user on a network with two or more linked servers to inject server-to-server commands that are executed with server authority.

    The vulnerability is being actively exploited; treat it as a priority. Update UnrealIRCd to version 6.2.7.1. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • UnrealIRCd lt *..6.2.7.1
    Fixed in
    • UnrealIRCd 6.2.7.1

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

    Metrics

    8.6

    XIEM Effective CVSS

    Highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    8.6

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org, EUVD, pwn.watch

    0.3 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 23.3

    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
    177.34 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
    8.6 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
    8.6
    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
    0.3 %
    Low — model estimates < 1% 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
    23.3
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    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 · automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 12 November 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-140

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This flaw is network-reachable without authentication or user interaction. Because the scope changes, any connected client gains server-level command authority, with a severe integrity impact across the whole IRC network: bans, kills, mode changes and channel takeovers. Modelled exploitation likelihood is comparatively low and no ransomware use is reported, but KEV listing confirms real-world attacks. Most NIS2 organisations have little exposure unless they run IRC at all. Where UnrealIRCd runs with linked servers — ops chat, community platforms, automation backbones — treat it as high priority and patch or apply the module blacklist within 24 hours. Single-server installations are not exploitable and can follow the regular patch cycle.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory: Find every UnrealIRCd instance, e.g. via ./unrealircd version in the install directory or by scanning for IRC ports (6667/6697 plus the server-link ports defined in listen {} blocks). Versions 6.0.0 through 6.2.7.0 are affected.
      • Patch: Upgrade to UnrealIRCd 6.2.7.1 (./unrealircd upgrade or build from the official release), then run ./unrealircd restart. Upgrade every linked server on the network. One unpatched hub or leaf is enough to serve as the injection point.
      • If you cannot patch right away: Disable the labeled-response module, e.g. with blacklist-module "labeled-response"; in unrealircd.conf, followed by a rehash or restart. Confirm that CAP LS no longer advertises labeled-response.
      • Emergency containment on suspected active abuse: Temporarily SQUIT server links and run servers standalone. Exploitation requires at least two linked servers.
      • Integrity check: Review active TKLs (STATS gline, STATS kline, STATS spamfilter), oper status and user modes for unexpected changes. If anything looks off, rotate the link {} block passwords and oper credentials.

    2. Runbook step 2

      Mitigation layers

      • Configuration change: Keep labeled-response blacklisted on every server in the network until all of them are upgraded. Functional impact: IRCv3 clients lose request/response correlation; normal chat keeps working.
      • Network segmentation: Bind server-to-server links to dedicated ports (listen { options { serversonly; } }) and firewall those ports to peer server IPs only. This does not stop injection through client connections, but it limits follow-on lateral activity.
      • Client access restriction: For internal IRC deployments (ops chat, bot infrastructure), restrict the client port to trusted networks or VPN. Use allow {} blocks and, where possible, require authentication so only authenticated users can connect, which shrinks the pool of potential attackers.
      • IPS/inline filtering (plaintext IRC on 6667 only): Add a Suricata rule on client flows that alerts on @label= tags with embedded control characters. Example: content:"@label="; pcre:"/@label=[^ ;]*(\\r|\\n|\\x0d|\\x0a)/";. On TLS (6697) this only works behind TLS termination.
      • Least privilege: Keep U-lines (ulines {}) and services links to the strict minimum, and detach unneeded leaf servers to reduce the blast radius of injected server commands.

    3. Runbook step 3

      Detection rules

      • UnrealIRCd logs (ircd.log or JSON logging): Hunt for server-sourced commands that don't map to an oper or services action: SVSKILL, SVSMODE, SVSJOIN, SVS2MODE, TKL +, SQUIT, KILL with a server as source. Example SPL: index=irc (SVSMODE OR SVSKILL OR "TKL +" OR SQUIT) NOT src IN (services.*).
      • Malformed label tags: Where raw/debug logging or packet capture is available, look for @label= values containing spaces, ;, \r, \n, or unusual length. Sigma shape: logsource: product: unrealircd, selection: message|contains: '@label=', filter: message|re: '@label=[A-Za-z0-9_-]{1,64}( |;)'.
      • Zeek/Suricata (plaintext IRC): Check Zeek irc.log and Suricata alerts for @label= followed by CR/LF sequences inside a single client message. Correlate bursts from one client immediately preceding server-level events such as kicks, bans or mode changes.
      • State anomalies: Run a scheduled diff of STATS gline, STATS spamfilter and oper lists against a baseline. New G-lines or spamfilters with no matching oper log entry are a strong exploitation signal.
      • Host level (auditd/EDR): Watch for writes to unrealircd.conf and conf/ includes, and for unrealircd restarts outside maintenance windows (auditctl -w /home/ircd/unrealircd/conf -p wa -k unrealircd_conf).

    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

    The labeled-response module in UnrealIRCd 6.0.0 before 6.2.7.1 does not escape the IRCv3 "label" message tag when echoing it into replies, which allows any user on a network with two or more linked servers to inject server-to-server commands that are executed with server authority.

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

    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
    UnrealIRCdUnrealIRCd
    • < 6.2.7.1
    • 6.2.7.1

    Vendors and products

    Weakness classes (CWE)

    • CWE-140Improper Neutralization of Delimiters

      Base

      The product does not neutralize or incorrectly neutralizes delimiters.

      Entry at MITRE CWE-140

    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

    • forums.unrealircd.orgUnrealIRCd 6.2.7.1 released & hot-patch to fix 9 security issues, including one CRITICAL (CVE-2026-114713)pwn-watch, euvd
    • unrealircd.orgeuvd
    • unrealircd.orgindex/newseuvd
    • pwn.watchpwn.watch: UnrealIRCd before 6.2.7.1: any normal user can run commands with server/IRCOp authority (critical CVE-2026-114713) plus 8 more fixespwn-watch
    • CVE.org (MITRE)CVE-2026-114713 record (CVSS 3.1 8.6, CWE-140)pwn-watch
    • openwall.comlists/oss-security/2026/11/08/1
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2026-1147…government-resource

    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. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: active, automatable: yes

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentremoved
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-13T19:16:29.356444Z"}
      —
      SSVC assessmentadded
      —
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-12T00:00:00+00:00"}

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

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: active, automatable: yes

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentremoved
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-13T19:02:57.473163Z"}
      —
      SSVC assessmentadded
      —
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-13T19:16:29.356444Z"}

      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
      —
      2026-11-13
      Due Dateadded
      —
      2026-11-13
      Required Actionadded
      —
      2026-11-13
      Vulnerability Nameadded
      —
      2026-11-13

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

    4. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: active, automatable: yes

      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-2026-114713
      SSVC assessmentremoved
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-12T00:00:00+00:00"}
      —
      SSVC assessmentadded
      —
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-13T19:02:57.473163Z"}

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

    5. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: yes

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentremoved
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-12T19:55:27.812651Z"}
      —
      SSVC assessmentadded
      —
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-12T00:00:00+00:00"}

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

    Show 3 older changes

    1. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: yes

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-114713","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-12T19:55:27.812651Z"}

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

    2. Record modifiedCVE Program

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      http://www.openwall.com/lists/oss-security/2026/11/08/1

      Source identifier: af854a3a-2127-422b-91ae-364da2661108

    3. ReceivedMITRE

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

      Weakness type: CWE-140

      Description added or changed

      Show 7 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      The labeled-response module in UnrealIRCd 6.0.0 before 6.2.7.1 does not escape the IRCv3 "label" message tag when echoing it into replies, which allows any user on a network with two or more linked servers to inject server-to-server commands that are executed with server authority.
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
      Weakness type (CWE)added
      —
      CWE-140
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/114xxx/CVE-2026-114713.json">CVE-2026-114713</a>
      Referenceadded
      —
      https://forums.unrealircd.org/viewtopic.php?t=9487
      Referenceadded
      —
      https://www.unrealircd.org/
      Referenceadded
      —
      https://www.unrealircd.org/index/news

      Source identifier: cve@mitre.org

    Linked advisories

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