VulnerabilityPublished 10 Nov 2026

CVE-2026-124910: Mozilla Firefox · Mitigation Bypass in the WebExtensions Component

Affects Mozilla FirefoxSource CVE Database V5

Compare

Not known to be exploited.

Data as of 10 Nov 2026, 13:50 UTC

Severity

High

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

Thin evidence

One scorer or none

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 10 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 Firefox to version 160 or later, or Firefox ESR 153.7 or later, to remediate this vulnerability. Applying the official vendor patch fully mitigates the issue. No additional mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-124910 is a mitigation bypass vulnerability in the WebExtensions component of Mozilla Firefox. This flaw was addressed and fixed in Firefox version 160 and Firefox ESR 153.7. The vulnerability could potentially allow attackers to bypass security mitigations implemented in the WebExtensions framework.

Impact

The vulnerability allows bypassing security mitigations in the WebExtensions component, which could lead to elevated risk of exploitation in Firefox browsers prior to version 160. The impact is rated high by Mozilla, suggesting potential for serious security consequences if exploited, though no active exploitation has been reported.

Summary

This vulnerability, identified as CVE-2026-124910, involves a mitigation bypass in the WebExtensions component of Mozilla Firefox. The issue was resolved in Firefox 160 and Firefox ESR 153.7. The vendor advisory classifies the impact as high, indicating the vulnerability could have significant security implications if exploited. No public exploit code or in-the-wild exploitation is currently known. The fix is included in the specified Firefox versions.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 10 Nov 2026, 13:50 UTC

Technical details

References

Community reviews

Related threats