CVE-2026-6763

Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS 3.1

6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 8% of CVEs (scores of 2026-10-25)

CWE

CWE-693

Published

2026-04-21

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• mozilla:firefox
• mozilla:thunderbird

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2021666
• https://www.mozilla.org/security/advisories/mfsa2026-30/
• https://www.mozilla.org/security/advisories/mfsa2026-32/
• https://www.mozilla.org/security/advisories/mfsa2026-33/
• https://www.mozilla.org/security/advisories/mfsa2026-34/

Check your stackJSON