Skip to main content
VulnerabilityPublished

CVE-2026-117920: Mozilla Firefox · Use-after-free in the DOM: HTML Parser component

Affects Mozilla FirefoxSource CVE Database V5

0

Not known to be exploited.

Data as of 27 Oct 2026, 17:24 UTC

Severity
High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 has been fixed. Applying these official updates fully mitigates the risk posed by this use-after-free flaw.

Description

CVE-2026-117920 is a use-after-free vulnerability in the DOM HTML Parser component of Mozilla Firefox. This flaw was addressed and fixed in Firefox version 159 and Firefox ESR 153.6. The vulnerability is categorized as high impact due to the potential risks associated with use-after-free bugs in memory management.

References

Community reviews

Loading reviews…