CVE-2026-117866

HIGH 7.3CVE-2026-117866 · Published 27/10/2026 · updated 04/11/2026

In short

CVE-2026-117866 is a HIGH (CVSS 7.3) vulnerability.
Chance of exploitation in the next 30 days (EPSS): 0.36%, higher than 29.7% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
—	No affected product versions are listed for this vulnerability yet.

Description

Privilege escalation due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

References

bugzilla.mozilla.org/show_bug.cgi
mozilla.org/security/advisories/mfsa2026-118
mozilla.org/security/advisories/mfsa2026-119
mozilla.org/security/advisories/mfsa2026-120
mozilla.org/security/advisories/mfsa2026-121
mozilla.org/security/advisories/mfsa2026-122

Running one of these products? Scan your site to see whether it exposes a vulnerable version.

Scan my site free