VulnerabilityPublished 27 Oct 2026

CVE-2026-117943: Use-after-free in the DOM · Core & HTML component

Source GCVE Database

Authoritative record:CVE-2026-117943· High

Not known to be exploited.

Data as of 27 Oct 2026, 17:28 UTC

Severity

High

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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-fw9c-6996-4c6j

What to do

AI-suggested

A fix for this vulnerability is available and has been incorporated in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying the official update.

Description

CVE-2026-117943 is a use-after-free vulnerability in the DOM Core and HTML components of Firefox. This security flaw was addressed and fixed in Firefox version 159 and the corresponding ESR releases 115.44 and 153.6. The vulnerability is rated with high impact by the vendor. No known exploits in the wild have been reported.

Impact

The vulnerability has a high impact rating, indicating that successful exploitation could lead to serious security consequences such as memory corruption, potentially enabling arbitrary code execution or browser compromise. However, no active exploitation in the wild has been reported to date.

Summary

This vulnerability involves a use-after-free condition in the DOM Core and HTML components of Firefox. Use-after-free bugs occur when a program continues to use a pointer after the memory it points to has been freed, potentially leading to memory corruption and security issues. Mozilla fixed this issue in Firefox 159 and the ESR versions 115.44 and 153.6. The advisory categorizes the impact as high, indicating a significant security risk if exploited.

References

Community reviews

Loading reviews…