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CVE-2025-55131 nodejs CVE debrief

CVE-2025-55131 is a high-severity vulnerability in Node.js that exposes uninitialized memory when allocations are interrupted, potentially leaking in-process secrets or causing data corruption. The flaw is related to the buffer allocation logic and can be exploited under specific timing conditions. This vulnerability affects Node.js versions and can be triggered when using the `vm` module with the timeout option. The vulnerability has a CVSS score of 7.1 and is considered high severity. Exploitation typically requires precise timing or in-process code execution but can become remotely exploitable under certain conditions.

Vendor
nodejs
Product
node
CVSS
HIGH 7.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-01-20
Original CVE updated
2026-07-15
Advisory published
2026-01-20
Advisory updated
2026-07-15

Who should care

Developers and administrators using Node.js are advised to take immediate action to mitigate this vulnerability. This vulnerability can lead to confidentiality and integrity impacts if exploited. Organizations relying on Node.js for their applications should prioritize patching and updating their systems.

Technical summary

The vulnerability is caused by a flaw in Node.js's buffer allocation logic, which can expose uninitialized memory when allocations are interrupted. This occurs when using the `vm` module with the timeout option. Buffers allocated with `Buffer.alloc` and other `TypedArray` instances like `Uint8Array` may contain leftover data from previous operations. Exploitation requires precise timing or in-process code execution but can become remotely exploitable when untrusted input influences workload and timeouts.

Defensive priority

High priority should be given to patching and mitigating this vulnerability due to its high severity and potential impact on confidentiality and integrity.

Recommended defensive actions

  • Apply the official patches or updates provided by Node.js to fix the buffer allocation logic flaw.
  • Review and update Node.js applications to ensure they are not using vulnerable versions of the `vm` module.
  • Implement additional monitoring and logging to detect potential exploitation attempts.
  • Consider implementing compensating controls, such as input validation and workload management, to reduce the risk of exploitation.
  • Perform thorough inventory checks to identify and update all affected Node.js instances.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability, its impact, and potential mitigations. Additional references from Node.js and Red Hat provide further details on the vulnerability and recommended actions.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-55131 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-55131

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2025-55131 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-55131

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://nodejs.org/en/blog/vulnerability/december-2025-security-releases

    [email protected]

  • Source reference

    Unverified legacy reference

    URL: https://access.redhat.com/errata/RHSA-2026:1842

    0b0ca135-0b70-47e7-9f44-1890c2a1c46c

  • Source reference

    Unverified legacy reference

    URL: https://access.redhat.com/errata/RHSA-2026:1843

    0b0ca135-0b70-47e7-9f44-1890c2a1c46c

  • Source reference

    Unverified legacy reference

    URL: https://access.redhat.com/errata/RHSA-2026:2420

    0b0ca135-0b70-47e7-9f44-1890c2a1c46c

  • Source reference

    Unverified legacy reference

    URL: https://access.redhat.com/errata/RHSA-2026:2421

    0b0ca135-0b70-47e7-9f44-1890c2a1c46c

  • Source reference

    Unverified legacy reference

    URL: https://access.redhat.com/errata/RHSA-2026:2422

    0b0ca135-0b70-47e7-9f44-1890c2a1c46c

  • Source reference

    Unverified legacy reference

    URL: https://access.redhat.com/errata/RHSA-2026:2767

    0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.