CVE-2026-117876: Mozilla Firefox · Use-after-free in the Layout: Text and Fonts component
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited.
Data as of 27 Oct 2026, 15:59 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 27 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
AI-suggested
Users and administrators should update Firefox to version 159 or later, or the corresponding ESR versions 115.44 or 153.6, where this vulnerability has been fixed. Applying these official updates fully mitigates the issue. No additional mitigation steps are required beyond applying the vendor-provided patches.
Description
CVE-2026-117876 is a use-after-free vulnerability in the Layout: Text and Fonts component of Mozilla Firefox. This security flaw was addressed and fixed in Firefox version 159 and the corresponding Firefox ESR versions 115.44 and 153.6. The vulnerability has a high impact rating according to the Mozilla advisory but there are no known exploits in the wild at this time.