HighCVE-2026-53613

    util-linux mount target TOCTOU allows local privilege escalation (CVE-2026-53613)

    Published Last modified Sources: BSI, SUSE, Msrc Update Guide, CVE.org, Debian, Ubuntu

    What is affected, what to do

    util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname.

    Update LANTIME to version V7.10.016, util-linux to version 2.42.

    Affected
    • Util-linux gte 2.17, <= 2.41.6..*

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

    Metrics

    7.0

    Priority

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

    Source: Vendor (CNA), CVSS v3

    7.0

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: BSI, SUSE, Msrc Update Guide, CVE.org, Debian, Ubuntu

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 5.5

    Show all metrics
    Severity
    High
    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
    65.24 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
    7.0 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
    7.0
    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
    0.2 %
    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
    5.5
    Low — this CVE sits in the lower 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
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 15 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-367

    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

    util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected.

    Source: BSI WID Portal, BSI CSAF, suse_csaf, Microsoft Security Update Guide, cvelistv5, NVD (NIST), CVE.org (MITRE), Debian Security Advisories, Ubuntu Security Notices

    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
    util-linuxutil-linux
    • ≥ 2.17, <= 2.41.6
    • —
    MeinbergLANTIME
    • < V7.10.016
    • V7.10.016
    Open Sourceutil-linux
    • < 2.42
    • 2.42

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianutil-linuxtrixie

    Weakness classes (CWE)

    • CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition

      Base

      The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

      Entry at MITRE CWE-367

    References & sources

    • github.comutil-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428gx_refsource_CONFIRM
    • github.comutil-linux/util-linux/commit/0b010025a0e429bc80355c94db86a84339…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd1…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba734…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa032…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e9565…x_refsource_MISC
    • github.comutil-linux/util-linux/commit/a9508d216eb8977979102782672e0470cc…x_refsource_MISC
    • github.comutil-linux/util-linux/releases/tag/v2.41.5x_refsource_MISC
    • github.comutil-linux/util-linux/releases/tag/v2.42.2x_refsource_MISC
    • github.comutil-linux/util-linux/releases/tag/v2.42.4x_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. 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-2026-53613","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T13:11:45.430649Z"}

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

    2. ReceivedGitHub

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

      Weakness type: CWE-367

      Description added or changed

      Show 18 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected.
      CVSSadded
      —
      AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
      Weakness type (CWE)added
      —
      CWE-367
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/53xxx/CVE-2026-53613.json">CVE-2026-53613</a>
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e3107c9
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e6a8d78
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac2c2ff5
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e956584bee9
      Referenceadded
      —
      https://github.com/util-linux/util-linux/commit/a9508d216eb8977979102782672e0470cc9bf2a2
      Referenceadded
      —
      https://github.com/util-linux/util-linux/releases/tag/v2.41.5
      Referenceadded
      —
      https://github.com/util-linux/util-linux/releases/tag/v2.42.2
      Referenceadded
      —
      https://github.com/util-linux/util-linux/releases/tag/v2.42.4
      Referenceadded
      —
      https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g

      Source identifier: security-advisories@github.com

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