CVE-2026-92045 Mozilla CVE debrief

Who should care

Defenders responsible for managing and securing Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR installations should assess exposure and apply patches to prevent potential sandbox escapes.

Why it matters

CVE-2026-92045 is a critical sandbox escape vulnerability in the WebRTC component of Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR. Defenders should prioritize verifying and applying patches to prevent potential exploitation.

• Potential sandbox escape, allowing for arbitrary code execution
• Elevation of privileges, potentially leading to further exploitation
• Data theft or tampering, if exploited in conjunction with other vulnerabilities
• Verification of patch application and system inventory to prevent exploitation

Technical summary

The vulnerability is caused by incorrect boundary conditions in the WebRTC component, allowing for a sandbox escape. It was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3. This critical vulnerability enables attackers to execute arbitrary code, potentially leading to elevation of privileges, data theft, or tampering. Defenders should prioritize verifying and applying patches to prevent potential sandbox escapes. The vulnerability's CVSS score of 9.6 indicates a high severity, emphasizing the need for immediate action.

Defensive priority

Defenders should prioritize verifying and applying patches for Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR to prevent potential sandbox escapes.

Recommended defensive actions

• Verify and apply patches for Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR
• Review and update inventory of affected systems
• Monitor for potential exploitation attempts
• Conduct vulnerability scanning to identify exposed systems
• Implement compensating controls for exposed systems
• Review system logs for signs of exploitation
• Track patch application and system inventory changes

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its CVSS score of 9.6 and severity of CRITICAL. Mozilla has provided security advisories (MFSA 2026-90, MFSA 2026-93, MFSA 2026-94, MFSA 2026-96) addressing the vulnerability.

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.