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PatchSiren cyber security CVE debrief

CVE-2026-109461 Microsoft CVE debrief

CVE-2026-109461 is an origin validation error in Microsoft Authentication Library (MSAL) for Node.js that allows an unauthorized attacker to disclose information over a network. The CVE record was published on 2026-10-16T18:17:31.150Z and has not been modified since then. The NVD entry is currently Awaiting Analysis. This vulnerability affects Node.js environments using MSAL, and defenders should assess exposure and prioritize verification of the vulnerability status. The error allows potential information disclosure over the network.

Vendor
Microsoft
Product
Microsoft Identity Client for NodeJS
CVSS
MEDIUM 5.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-16
Original CVE updated
2026-10-17
Advisory published
2026-10-16
Advisory updated
2026-10-17

Who should care

Defenders responsible for Node.js environments using MSAL should assess exposure and prioritize verification of the vulnerability status. They should review and implement secure authentication and authorization mechanisms, and monitor for potential information disclosure attempts. This includes verifying the vulnerability status, assessing exposure, and implementing mitigations where necessary.

Why it matters

CVE-2026-109461 is an origin validation error in Microsoft Authentication Library (MSAL) for Node.js that allows an unauthorized attacker to disclose information over a network. Defenders should prioritize verifying the vulnerability status and assessing exposure in their Node.js environments using MSAL.

  • Potential information disclosure over the network
  • Verification of vulnerability status and affected versions is required
  • Assessment of exposure in Node.js environments using MSAL is necessary

Technical summary

The CVE-2026-109461 vulnerability is an origin validation error in Microsoft Authentication Library (MSAL) for Node.js. This error allows an unauthorized attacker to disclose information over a network. The vulnerability affects Node.js environments using MSAL, and defenders should prioritize verifying the vulnerability status and assessing exposure. The technical impact is potential information disclosure, and the vulnerability requires verification of affected versions and assessment of exposure.

Defensive priority

Defenders should prioritize verifying the vulnerability status and assessing exposure in their Node.js environments using MSAL.

Recommended defensive actions

  • Verify the vulnerability status and assess exposure in Node.js environments using MSAL
  • Review and implement secure authentication and authorization mechanisms
  • Monitor for potential information disclosure attempts

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further verification is required to determine the affected versions and potential impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-109461 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-109461

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

  • CVE-2026-109461 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-109461

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

Supplemental references

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.