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PatchSiren cyber security CVE debrief

CVE-2026-109769 Mozilla CVE debrief

Information disclosure vulnerability in Firefox's Networking: Cache component, fixed in Firefox 158. This issue allows unintended access to sensitive data, potentially leading to privacy and security risks. Defenders should assess exposure and apply the fix to prevent potential information disclosure incidents. The vulnerability was confirmed and addressed in Firefox 158, emphasizing the importance of keeping software up-to-date. It is crucial for defenders to verify exposure and apply necessary patches promptly.

Vendor
Mozilla
Product
Firefox
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-13
Original CVE updated
2026-10-13
Advisory published
2026-10-13
Advisory updated
2026-10-13

Who should care

Defenders responsible for Firefox deployments should assess exposure and apply the fix to prevent potential information disclosure incidents.

Why it matters

Information disclosure vulnerability in Firefox's Networking: Cache component, fixed in Firefox 158. Defenders should prioritize verifying exposure and applying the fix.

  • Verify exposure by checking Firefox versions prior to 158
  • Apply the fix to prevent potential information disclosure incidents
  • Monitor for potential information disclosure incidents

Technical summary

The vulnerability is an information disclosure issue in the Networking: Cache component of Firefox, which was fixed in Firefox 158. This issue arises from the component's handling of cache data, potentially allowing unauthorized access to sensitive information. The fix in Firefox 158 addresses this vulnerability, emphasizing the need for timely software updates to mitigate potential risks. Defenders should prioritize verifying exposure and applying the fix to prevent information disclosure incidents.

Defensive priority

Defenders should prioritize verifying exposure and applying the fix, as the vulnerability may allow information disclosure.

Recommended defensive actions

  • Verify exposure by checking if Firefox versions prior to 158 are in use
  • Apply the fix by updating Firefox to version 158 or later
  • Monitor for potential information disclosure incidents

Evidence notes

The CVE record and source item provide limited information about the vulnerability, but confirm it was fixed in Firefox 158. The vulnerability affects the Networking: Cache component of Firefox, and its disclosure highlights the need for vigilance in maintaining software updates. Evidence is based on official CVE and source item descriptions, with limitations noted in detailed technical analysis. Further verification is recommended to ensure comprehensive exposure assessment.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-109769 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-109769

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

  • CVE-2026-109769 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-109769

    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.