PatchSiren cyber security CVE debrief
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
-
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.