Vulnerability · Published Sep 29, 2026 · Assigned by mozilla

CVE-2026-100782Privilege escalation due to incorrect boundary conditions in the Graphics component

High 8.8

In plain English

A high-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 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.3%top 82.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Privilege escalation due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, 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:10thunderbird140.17.0-1.el10_2.alma.1ALSA-2026:80674
AlmaLinux:8thunderbird140.17.0-1.el8_10.alma.1ALSA-2026:90913
AlmaLinux:9thunderbird140.17.0-1.el9_8.alma.1ALSA-2026:80694
Debian:12firefox-esr153.4.0esr-1~deb12u1DEBIAN-CVE-2026-100782
Debian:13firefox-esr153.4.0esr-1~deb13u1DEBIAN-CVE-2026-100782
Debian:14firefox-esr153.4.0esr-1DEBIAN-CVE-2026-100782
Debian:12thunderbird1:140.17.0esr-1~deb12u1DEBIAN-CVE-2026-100782
Debian:13thunderbird1:140.17.0esr-1~deb13u1DEBIAN-CVE-2026-100782
Debian:14thunderbird1:153.4.0esr-1DEBIAN-CVE-2026-100782
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:10thunderbird0:140.17.0-1.el10_2RLSA-2026:80674
Rocky Linux:8thunderbird0:140.17.0-1.el8_10RLSA-2026:90913
Rocky Linux:9thunderbird0:140.17.0-1.el9_8RLSA-2026:80694
Ubuntu:22.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-100782
Ubuntu:24.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-100782
Ubuntu:24.04:LTSmozjs115no fix listedUBUNTU-CVE-2026-100782
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2026-100782
Ubuntu:22.04:LTSmozjs91no fix listedUBUNTU-CVE-2026-100782
Ubuntu:22.04:LTSthunderbirdno fix listedUBUNTU-CVE-2026-100782

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:U/C:H/I:H/A:H

References