CVE-2026-8974
published 2026-05-19CVE-2026-8974: Memory safety bugs present in Firefox ESR 140.10 and Firefox 150. Some of these bugs showed evidence of memory corruption and we presume that with enough…
PriorityP348high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.33%
25.5th percentile
Memory safety bugs present in Firefox ESR 140.10 and 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, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 151 | Firefox 151 |
| mozilla | firefox | < 140.11.0 | 140.11.0 |
| mozilla | firefox | < 151.0.0 | 151.0.0 |
| mozilla | firefox | — | — |
| mozilla | firefox_esr | < Firefox ESR 140.11 | Firefox ESR 140.11 |
| mozilla | thunderbird | < Thunderbird 140.11 | Thunderbird 140.11 |
| mozilla | thunderbird | < Thunderbird 151 | Thunderbird 151 |
| mozilla | thunderbird | < 140.11 | 140.11 |
| mozilla | thunderbird | < 151.0.0 | 151.0.0 |
| rhel10 | firefox-flatpak | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vendor_redhat8.8HIGH
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Red Hat
firefox: Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151
vendor_redhat·2026-05-19·CVSS 8.8
CVE-2026-8974 [HIGH] CWE-787 firefox: Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151
firefox: Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:
Memory safety bugs present in Firefox ESR 140.10 and 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.
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Package: firefox (Red Hat Enterprise Linux 7) - Affected
Package: f
Mozilla
Mozilla Foundation Security Advisory 2026-51: CVE-2026-8974
vendor_mozilla·CVSS 9.8
CVE-2026-8974 [CRITICAL] Mozilla Foundation Security Advisory 2026-51: CVE-2026-8974
Mozilla Foundation Security Advisory 2026-51
CVE: CVE-2026-8974
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.11
Mozilla
Mozilla Foundation Security Advisory 2026-48: CVE-2026-8974
vendor_mozilla·CVSS 9.8
CVE-2026-8974 [CRITICAL] Mozilla Foundation Security Advisory 2026-48: CVE-2026-8974
Mozilla Foundation Security Advisory 2026-48
CVE: CVE-2026-8974
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.11
Mozilla
Mozilla Foundation Security Advisory 2026-50: CVE-2026-8974
vendor_mozilla·CVSS 9.8
CVE-2026-8974 [CRITICAL] Mozilla Foundation Security Advisory 2026-50: CVE-2026-8974
Mozilla Foundation Security Advisory 2026-50
CVE: CVE-2026-8974
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 151
Mozilla
Mozilla Foundation Security Advisory 2026-46: CVE-2026-8974
vendor_mozilla·CVSS 9.8
CVE-2026-8974 [CRITICAL] Mozilla Foundation Security Advisory 2026-46: CVE-2026-8974
Mozilla Foundation Security Advisory 2026-46
CVE: CVE-2026-8974
Product: Firefox
Impact: high
Fixed in: Firefox 151
VulDB
Mozilla Firefox up to 150 memory corruption (Nessus ID 315327)
vuldb·2026-05-20·CVSS 9.8
CVE-2026-8974 [CRITICAL] Mozilla Firefox up to 150 memory corruption (Nessus ID 315327)
A vulnerability was found in Mozilla Firefox up to 150 and classified as critical. This impacts an unknown function. Executing a manipulation can lead to memory corruption.
This vulnerability appears as CVE-2026-8974. The attack may be performed from remote. There is no available exploit.
It is suggested to upgrade the affected component.
GHSA
GHSA-c792-chx5-8443: Memory safety bugs present in Firefox ESR 140
ghsa_unreviewed·2026-05-19
CVE-2026-8974 [CRITICAL] CWE-119 GHSA-c792-chx5-8443: Memory safety bugs present in Firefox ESR 140
Memory safety bugs present in Firefox ESR 140.10 and 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 Firefox ESR 140.11.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1784128%2C1883230%2C1983677%2C2022390%2C2023116%2C2023657%2C2024255%2C2024418%2C2024441%2C2024447%2C2024966%2C2025412%2C2025467%2C2025940%2C2025950%2C2025956%2C2026284%2C2027247%2C2027255%2C2027288%2C2027306%2C2027322%2C2027332%2C2027333%2C2028266%2C2028292%2C2028319%2C2028526%2C2028870%2C2028876%2C2028882%2C2029062%2C2029309%2C2029414%2C2029422%2C2029428%2C2029447%2C2029732%2C2029785%2C2029793%2C2029813%2C2029899%2C2031028%2C2031457%2C2032039%2C2033610%2C2033854%2C2034498%2C2034628%2C2034978%2C2035966%2C2036668%2C2036905%2C2036930https://www.mozilla.org/security/advisories/mfsa2026-46/https://www.mozilla.org/security/advisories/mfsa2026-48/https://www.mozilla.org/security/advisories/mfsa2026-50/https://www.mozilla.org/security/advisories/mfsa2026-51/
2026-05-19
Published