CriticalCVE-2026-62948

    OpenWRT: Improper Neutralization of Escape, Meta, or Control Sequences (CVE-2026-62948)

    Published Last modified Sources: CVE.org

    What is affected, what to do

    OpenWrt is a Linux operating system targeting embedded devices. Prior to 25.12.5, odhcpd writes a DHCPv6 client FQDN option 39 hostname into /tmp/odhcpd.leases through src/statefiles.c statefiles_write_state6() and statefiles_write_state4() without escaping, allowing newline injection of forged lease lines that LuCI rpcd-mod-luci getDHCPLeases displays through htdocs/luci-static/resources/view/status/include/40_dhcp.js and htdocs/luci-static/resources/luci.js dom.append as live HTML in the Active DHCPv6 Leases admin page.

    Update OpenWRT to version 25.12.5.

    Affected
    • OpenWRT lt *..25.12.5
    Fixed in
    • OpenWRT 25.12.5

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

    Metrics

    9.6

    Priority

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

    Source: NVD, CVSS v3

    9.6

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: CVE.org

    0.6 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 47.5

    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
    86.94 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
    no public PoC known
    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
    9.6 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
    9.6
    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
    0.6 %
    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
    47.5
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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
    —
    Published
    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-79, CWE-117, CWE-150

    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
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    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
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    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

    OpenWrt is a Linux operating system targeting embedded devices. Prior to 25.12.5, odhcpd writes a DHCPv6 client FQDN option 39 hostname into /tmp/odhcpd.leases through src/statefiles.c statefiles_write_state6() and statefiles_write_state4() without escaping, allowing newline injection of forged lease lines that LuCI rpcd-mod-luci getDHCPLeases displays through htdocs/luci-static/resources/view/status/include/40_dhcp.js and htdocs/luci-static/resources/luci.js dom.append as live HTML in the Active DHCPv6 Leases admin page. This vulnerability is fixed in 25.12.5.

    Source: cvelistv5, NVD (NIST), CVE.org (MITRE)

    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
    openwrtopenwrt
    • < 25.12.5
    • 25.12.5

    Vendors and products

    Affected operating systems

    Affected operating systems
    Otheropenwrtopenwrt—

    Weakness classes (CWE)

    • CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

      Base

      The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

      Entry at MITRE CWE-79

    • CWE-117Improper Output Neutralization for Logs

      Base

      The product constructs a log message from external input, but it does not neutralize or incorrectly neutralizes special elements when the message is written to a log file.

      Entry at MITRE CWE-117

    • CWE-150Improper Neutralization of Escape, Meta, or Control Sequences

      Variant

      The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.

      Entry at MITRE CWE-150

    References & sources

    • github.comopenwrt/openwrt/security/advisories/GHSA-hhmc-92hw-535fx_refsource_CONFIRM
    • github.comopenwrt/odhcpd/pull/404x_refsource_MISC
    • github.comopenwrt/luci/commit/55379d04fcc3c605003a5001d6135cf02ae6048ax_refsource_MISC
    • github.comopenwrt/odhcpd/commit/68f382690bfaec56d5b1f31c3c31c48bcb642e3ax_refsource_MISC
    • github.comopenwrt/openwrt/releases/tag/v25.12.5x_refsource_MISC

    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. Initial analysis by NVDNVD

      Newly listed as affected:
      Show 7 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationadded
      —
      OR *cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:* versions up to (excluding) 25.12.5
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/openwrt/luci/commit/55379d04fcc3c605003a5001d6135cf02ae6048a Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/openwrt/odhcpd/commit/68f382690bfaec56d5b1f31c3c31c48bcb642e3a Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/openwrt/odhcpd/pull/404 Types: Issue Tracking, Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/openwrt/openwrt/releases/tag/v25.12.5 Types: Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/openwrt/openwrt/security/advisories/GHSA-hhmc-92hw-535f Types: Exploit, Mitigation, Vendor Advisory
      Reference typeadded
      —
      CISA-ADP: https://github.com/openwrt/openwrt/security/advisories/GHSA-hhmc-92hw-535f Types: Exploit, Mitigation, Vendor Advisory

      Source identifier: nvd@nist.gov

    2. ReceivedGitHub

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

      Weakness type: CWE-79, CWE-117, CWE-150

      Description added or changed

      Show 11 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      openwrt
      Descriptionadded
      —
      OpenWrt is a Linux operating system targeting embedded devices. Prior to 25.12.5, odhcpd writes a DHCPv6 client FQDN option 39 hostname into /tmp/odhcpd.leases through src/statefiles.c statefiles_write_state6() and statefiles_write_state4() without escaping, allowing newline injection of forged lease lines that LuCI rpcd-mod-luci getDHCPLeases displays through htdocs/luci-static/resources/view/status/include/40_dhcp.js and htdocs/luci-static/resources/luci.js dom.append as live HTML in the Active DHCPv6 Leases admin page. This vulnerability is fixed in 25.12.5.
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
      Weakness type (CWE)added
      —
      CWE-79
      Weakness type (CWE)added
      —
      CWE-117
      Weakness type (CWE)added
      —
      CWE-150
      Referenceadded
      —
      https://github.com/openwrt/luci/commit/55379d04fcc3c605003a5001d6135cf02ae6048a
      Referenceadded
      —
      https://github.com/openwrt/odhcpd/commit/68f382690bfaec56d5b1f31c3c31c48bcb642e3a
      Referenceadded
      —
      https://github.com/openwrt/odhcpd/pull/404
      Referenceadded
      —
      https://github.com/openwrt/openwrt/releases/tag/v25.12.5
      Referenceadded
      —
      https://github.com/openwrt/openwrt/security/advisories/GHSA-hhmc-92hw-535f

      Source identifier: security-advisories@github.com

    Linked advisories

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