Vulnerability · Published Sep 15, 2026 · Assigned by mozilla

CVE-2026-92035Sandbox escape due to incorrect boundary conditions in the Graphics component

Critical 9.6

In plain English

A critical-severity memory corruption in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.6Critical
Exploit odds (30 days)0.3%top 73.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Thunderbird 140.17, Firefox 156, Firefox ESR 153.3, Thunderbird 156, Thunderbird 153.3, Firefox ESR 115.42, and Firefox ESR 140.17.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10firefox140.17.0-1.el10_2ALSA-2026:76764
AlmaLinux:8firefox140.17.0-1.el8_10.alma.1ALSA-2026:76850
AlmaLinux:9firefox140.17.0-1.el9_8.alma.1ALSA-2026:76761
AlmaLinux:9firefox-x11140.17.0-1.el9_8.alma.1ALSA-2026:76761
AlmaLinux:8thunderbird140.17.0-1.el8_10.alma.1ALSA-2026:90913
Debian:12thunderbird1:140.17.0esr-1~deb12u1DEBIAN-CVE-2026-92035
Debian:13thunderbird1:140.17.0esr-1~deb13u1DEBIAN-CVE-2026-92035
Debian:14thunderbird1:153.3.0esr-1DEBIAN-CVE-2026-92035
Rocky Linux:10firefox0:140.17.0-1.el10_2RLSA-2026:76764
Rocky Linux:8firefox0:140.17.0-1.el8_10RLSA-2026:76850
Rocky Linux:9firefox0:140.17.0-1.el9_8RLSA-2026:76761
Rocky Linux:8thunderbird0:140.17.0-1.el8_10RLSA-2026:90913
Ubuntu:22.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-92035
Ubuntu:24.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-92035
Ubuntu:24.04:LTSmozjs115no fix listedUBUNTU-CVE-2026-92035
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2026-92035
Ubuntu:22.04:LTSmozjs91no fix listedUBUNTU-CVE-2026-92035
Ubuntu:22.04:LTSthunderbirdno fix listedUBUNTU-CVE-2026-92035

Affected products (as reported)

VendorProductVersions
Mozilla Firefox see references
Mozilla Thunderbird see references

Weakness: CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

References