CVE-2026-74957
published 2026-08-18CVE-2026-74957: Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154…
PriorityP342high8.1CVSS 3.1
AVNACLPRNUIRSUCHIHAN
EPSS
0.30%
22.6th percentile
Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 154 | Firefox 154 |
| mozilla | firefox | < 140.14.0 | 140.14.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 141.0 < 153.1.0 | 153.1.0 |
| mozilla | firefox_esr | < Firefox ESR 153.1 | Firefox ESR 153.1 |
| mozilla | firefox_esr | < Firefox ESR 140.14 | Firefox ESR 140.14 |
| mozilla | thunderbird | < Thunderbird 140.14 | Thunderbird 140.14 |
| mozilla | thunderbird | < Thunderbird 154 | Thunderbird 154 |
| mozilla | thunderbird | < Thunderbird 153.1 | Thunderbird 153.1 |
| mozilla | thunderbird | < 140.14.0 | 140.14.0 |
| mozilla | thunderbird | — | — |
| mozilla | thunderbird | >= 141.0 < 153.1.0 | 153.1.0 |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.18.1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
vendor_redhat6.1MEDIUM
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Red Hat
firefox: thunderbird: Mitigation bypass in the Safe Browsing component
vendor_redhat·2026-08-18·CVSS 6.1
CVE-2026-74957 [MEDIUM] CWE-807 firefox: thunderbird: Mitigation bypass in the Safe Browsing component
firefox: thunderbird: Mitigation bypass in the Safe Browsing component
Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Mitigation bypass in the Safe Browsing component
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: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: thunderbird (Red
Mozilla
Mozilla Foundation Security Advisory 2026-77: CVE-2026-74957
vendor_mozilla
CVE-2026-74957 Mozilla Foundation Security Advisory 2026-77: CVE-2026-74957
Mozilla Foundation Security Advisory 2026-77
CVE: CVE-2026-74957
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-74: CVE-2026-74957
vendor_mozilla
CVE-2026-74957 Mozilla Foundation Security Advisory 2026-74: CVE-2026-74957
Mozilla Foundation Security Advisory 2026-74
CVE: CVE-2026-74957
Product: Firefox
Impact: high
Fixed in: Firefox 154
Mozilla
Mozilla Foundation Security Advisory 2026-79: CVE-2026-74957
vendor_mozilla
CVE-2026-74957 Mozilla Foundation Security Advisory 2026-79: CVE-2026-74957
Mozilla Foundation Security Advisory 2026-79
CVE: CVE-2026-74957
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.14
Mozilla
Mozilla Foundation Security Advisory 2026-78: CVE-2026-74957
vendor_mozilla
CVE-2026-74957 Mozilla Foundation Security Advisory 2026-78: CVE-2026-74957
Mozilla Foundation Security Advisory 2026-78
CVE: CVE-2026-74957
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 154
Mozilla
Mozilla Foundation Security Advisory 2026-80: CVE-2026-74957
vendor_mozilla
CVE-2026-74957 Mozilla Foundation Security Advisory 2026-80: CVE-2026-74957
Mozilla Foundation Security Advisory 2026-80
CVE: CVE-2026-74957
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-76: CVE-2026-74957
vendor_mozilla
CVE-2026-74957 Mozilla Foundation Security Advisory 2026-76: CVE-2026-74957
Mozilla Foundation Security Advisory 2026-76
CVE: CVE-2026-74957
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.14
GHSA
Mitigation bypass in the Safe Browsing component.
ghsa_unreviewed·2026-08-18
CVE-2026-74957 Mitigation bypass in the Safe Browsing component.
Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2041906https://www.mozilla.org/security/advisories/mfsa2026-74/https://www.mozilla.org/security/advisories/mfsa2026-76/https://www.mozilla.org/security/advisories/mfsa2026-77/https://www.mozilla.org/security/advisories/mfsa2026-78/https://www.mozilla.org/security/advisories/mfsa2026-79/https://www.mozilla.org/security/advisories/mfsa2026-80/
2026-08-18
Published