CVE-2026-117933: Mozilla Firefox · Frame poisoning in the CSS Parsing and Computation component
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited.
Data as of 27 Oct 2026, 17:24 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 should update their Firefox installations to version 159 or later, or Firefox ESR 153.6 or later, where this vulnerability has been fixed. No additional mitigation steps are indicated by Mozilla.
Description
CVE-2026-117933 is a high-impact vulnerability involving frame poisoning in the CSS Parsing and Computation component of Mozilla Firefox. The issue was addressed and fixed in Firefox version 159 and Firefox ESR 153.6. No exploits in the wild have been reported. Users are advised to update to the fixed versions to mitigate the risk.