CVE-2026-8973

HIGH

Firefox and Thunderbird < 151 - Memory Corruption

Title source: llm

Description

Memory safety bugs present in Firefox 150. 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 was fixed in Firefox 151 and Thunderbird 151.

References (6)

Core 6

Core References

Vendor Advisory

https://access.redhat.com/security/cve/CVE-2026-8973

Vendor Advisory

https://bugzilla.redhat.com/show_bug.cgi?id=2479864

Vendor Advisory

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8973.json

Memory safety bugs fixed in Thunderbird 151

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1362365%2C1860538%2C1929005%2C1983353%2C1998526%2C2023271%2C2023943%2C2024244%2C2024260%2C2024443%2C2024665%2C2024774%2C2024916%2C2025346%2C2025357%2C2025406%2C2025434%2C2025488%2C2025496%2C2025942%2C2025947%2C2025968%2C2026279%2C2027159%2C2027239%2C2027276%2C2027308%2C2027310%2C2027324%2C2027329%2C2027363%2C2027381%2C2027382%2C2027383%2C2028274%2C2028884%2C2029060%2C2029065%2C2029068%2C2029281%2C2029293%2C2029297%2C2029303%2C2029439%2C2029448%2C2029703%2C2029720%2C2029721%2C2029723%2C2029770%2C2029771%2C2029782%2C2029818%2C2029885%2C2030100%2C2030379%2C2030385%2C2030979%2C2031119%2C2031122%2C2034119%2C2034791%2C2035209%2C2036666%2C2037986

https://www.mozilla.org/security/advisories/mfsa2026-46/

https://www.mozilla.org/security/advisories/mfsa2026-50/

Scores

CVSS v3 8.8

EPSS 0.0034

EPSS Percentile 25.5%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-119 CWE-787

Status published

Products (4)

mozilla/firefox < 151.0.0

Mozilla/Firefox 151

mozilla/thunderbird < 151.0.0

Mozilla/Thunderbird 151

Published May 19, 2026

Tracked Since May 19, 2026