VulnerabilityPublished 27 Oct 2026

CVE-2026-117946: Mozilla Firefox · Incorrect boundary conditions in the JavaScript Engine component

Affects Mozilla FirefoxSource CVE Database V5

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

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.

What to do

AI-suggested

Users and administrators should update Mozilla Firefox to version 159 or later, or to Firefox ESR versions 115.44 or 153.6 or later, where this vulnerability has been fixed. Applying these official updates fully mitigates the vulnerability. No additional mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-117946 is a high-impact vulnerability involving incorrect boundary conditions in the JavaScript Engine component of Mozilla Firefox. This flaw was addressed and fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6. The vulnerability could potentially lead to security issues if exploited, but no known exploits in the wild have been reported.

Impact

The vulnerability has a high impact rating according to the Mozilla advisory. Incorrect boundary conditions in the JavaScript Engine could lead to potential security risks such as memory corruption or privilege escalation, though no active exploitation has been reported. Users running affected versions prior to the fixed releases are at risk until they apply the update.

Summary

This vulnerability concerns incorrect boundary conditions in the JavaScript Engine component of Mozilla Firefox. The issue was identified and fixed in Firefox 159 and corresponding ESR versions 115.44 and 153.6. The Mozilla advisory classifies the impact as high. No specific exploitation details or attack vectors are provided in the advisory or CVE description. The fix is included in the stated Firefox versions, mitigating the risk for users who have updated accordingly.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 27 Oct 2026, 15:00 UTC

Technical details

References

Community reviews

Related threats