CVE-2026-92024 Mozilla CVE debrief

Who should care

Defenders responsible for managing Firefox, Firefox ESR, and Thunderbird installations should assess exposure and prioritize updates to patched versions. This includes operators, platform administrators, vulnerability management teams, and security teams who need to verify affected versions in use and apply patches or mitigations accordingly.

Why it matters

CVE-2026-92024 is a high-severity use-after-free vulnerability in the SVG component of Firefox, Firefox ESR, and Thunderbird. Defenders should prioritize updating to patched versions to prevent potential exploitation.

• Potential for code execution after exploitation
• Need for verification of affected versions in use
• Priority for updating to patched versions to prevent exploitation
• Importance of monitoring for potential attacks targeting this vulnerability

Technical summary

The CVE-2026-92024 vulnerability involves a use-after-free issue in the SVG component of Firefox, Firefox ESR, and Thunderbird. This vulnerability has been addressed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3. Defenders should assess exposure, particularly for systems using affected versions, and prioritize updates to patched versions to prevent potential exploitation. The vulnerability has a high-severity CVSS score of 8.8 and is classified as HIGH.

Defensive priority

High priority for updating to patched versions

Recommended defensive actions

• Update Firefox to version 156 or later
• Update Firefox ESR to version 115.41 or later
• Update Thunderbird to version 156 or later
• Verify and apply patches for Firefox ESR 140.16, Firefox ESR 153.3, and Thunderbird 140.16, Thunderbird 153.3
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Mozilla's security advisories (MFSA2026-90 to MFSA2026-96) offer additional information on the patched versions. Defenders should verify affected versions in use and prioritize updates to patched versions. The vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3. Evidence is limited to public CVE and NVD data.

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.