CVE-2026-92005 Mozilla CVE debrief

Who should care

Defenders responsible for managing and securing Firefox, Firefox ESR, and Thunderbird installations should assess exposure and apply patches accordingly. This includes reviewing and updating inventory of affected systems and components, monitoring for potential exploitation attempts and anomalies, and verifying and applying patches to the latest versions. Security teams and vulnerability management teams should prioritize this vulnerability and ensure that

Why it matters

A use-after-free vulnerability in the Audio/Video: Web Codecs component of Firefox, Firefox ESR, and Thunderbird has been addressed. Defenders should prioritize verifying and applying the provided patches to mitigate potential risks associated with this vulnerability.

• Verify and apply patches to prevent potential exploitation.
• Review and update inventory of affected systems and components.
• Monitor for potential exploitation attempts and anomalies.

Technical summary

The vulnerability is a use-after-free issue in the Audio/Video: Web Codecs component of Firefox, Firefox ESR, and Thunderbird. This was addressed in Firefox 156, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3. The vulnerability could potentially allow for code execution, and defenders should prioritize verifying and applying the provided patches to mitigate potential risks associated with this vulnerability. Affected product context and defensive impact were considered in the development of patches.

Defensive priority

Defenders should prioritize verifying and applying the provided patches to mitigate potential risks associated with this vulnerability.

Recommended defensive actions

• Verify and apply patches for Firefox, Firefox ESR, and Thunderbird to the latest versions.
• Review and update inventory of affected systems and components.
• Monitor for potential exploitation attempts and anomalies.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and NVD vulnerability detail provide information on the use-after-free vulnerability in the Audio/Video: Web Codecs component. Vendor advisories from Mozilla offer additional context and mitigation strategies.

Sources and 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.