CVE-2026-117991: Mozilla Firefox · Incorrect boundary conditions in the Layout: Text and Fonts component
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited.
Data as of 27 Oct 2026, 14:44 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 Firefox ESR 153.6 or later, where this vulnerability is fixed. Applying these official patches fully mitigates the risk from this vulnerability.
Description
CVE-2026-117991 is a vulnerability in the Layout: Text and Fonts component of Mozilla Firefox. It involves incorrect boundary conditions that could potentially lead to security issues. This vulnerability has been fixed in Firefox version 159 and Firefox ESR 153.6. The impact is rated high by Mozilla.