CVE-2026-2793

CRITICAL

Firefox/Thunderbird ESR - Memory Corruption

Title source: llm

Description

Memory safety bugs present in Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

References (6)

[Issue Tracking] https://bugzilla.mozilla.org/buglist.cgi?bug_id=2015196%2C2016423%2C2016498

[Vendor Advisory] https://www.mozilla.org/security/advisories/mfsa2026-13/

[Vendor Advisory] https://www.mozilla.org/security/advisories/mfsa2026-14/

[Vendor Advisory] https://www.mozilla.org/security/advisories/mfsa2026-15/

[Vendor Advisory] https://www.mozilla.org/security/advisories/mfsa2026-16/

[Vendor Advisory] https://www.mozilla.org/security/advisories/mfsa2026-17/

Scores

CVSS v3 9.8

EPSS 0.0006

EPSS Percentile 20.0%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

CWE

CWE-787

Status published

Affected Products (4)

mozilla/firefox < 115.33.0

mozilla/firefox < 148.0

mozilla/thunderbird < 140.8.0

mozilla/thunderbird < 148.0

Timeline

Published Feb 24, 2026

Tracked Since Feb 24, 2026