Skip to main content
VulnerabilityPublished Updated

CVE-2026-100781: Mozilla Firefox · Memory Buffer Overflow

Affects Mozilla FirefoxSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 9.6 Critical.

Data as of 13 Nov 2026, 23:53 UTC

CVSS 3.1 base score
9.6Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 29 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: 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 13 Nov 2026.

What to do

AI-suggested

Mozilla has issued official fixes for this vulnerability in Firefox ESR 153.4, Firefox 157, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox ESR 115.42, and Firefox ESR 140.17. Users and administrators should update to these fixed versions to remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-100781 is a critical sandbox escape vulnerability in Mozilla Firefox's Graphics: WebRender component caused by incorrect boundary conditions. It allows an attacker to potentially escape the sandbox environment, impacting confidentiality, integrity, and availability. The issue has been fixed in multiple Firefox and Thunderbird versions including Firefox ESR 153.4 and Firefox 157.

References

Community reviews

Loading reviews…