Protection mechanism failure in Mozilla products - CVE-2026-74979

Vulnerability identifier: #VU144090

CSH Severity: Medium

CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-74979

CWE-ID: CWE-693

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass a security mitigation.

The vulnerability exists due to a protection mechanism failure in the Add-ons Manager component when handling crafted web content. A remote attacker can cause the victim to visit a specially crafted website to bypass a security mitigation.

User interaction is required to visit a crafted website or URL.

Firefox for Android
Mozilla Firefox
Firefox ESR
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
Desktop Applications Module
Basesystem Module
openSUSE Leap
Mozilla Thunderbird
rust-cbindgen-debugsource
rust-cbindgen
rust-cbindgen-debuginfo
libsoftokn3-debuginfo-32bit
mozilla-nss-certs-32bit
mozilla-nss-debuginfo
mozilla-nss-certs-debuginfo-32bit
libsoftokn3-32bit
libfreebl3-debuginfo-32bit
mozilla-nss-tools-debuginfo
mozilla-nss
libfreebl3
mozilla-nss-sysinit
mozilla-nss-debuginfo-32bit
mozilla-nss-sysinit-32bit
mozilla-nss-sysinit-debuginfo-32bit
mozilla-nss-tools
mozilla-nss-sysinit-debuginfo
libsoftokn3-debuginfo
mozilla-nss-certs
libfreebl3-debuginfo
mozilla-nss-certs-debuginfo
libsoftokn3
mozilla-nss-debugsource
mozilla-nss-devel
libfreebl3-32bit
mozilla-nss-32bit
mozilla-nss-32bit-debuginfo
libfreebl3-32bit-debuginfo
mozilla-nss-sysinit-32bit-debuginfo
libsoftokn3-64bit
mozilla-nss-certs-64bit-debuginfo
mozilla-nss-sysinit-64bit-debuginfo
mozilla-nss-certs-64bit
mozilla-nss-sysinit-64bit
libsoftokn3-64bit-debuginfo
libfreebl3-64bit-debuginfo
libfreebl3-64bit
mozilla-nss-64bit-debuginfo
mozilla-nss-64bit
libsoftokn3-32bit-debuginfo
mozilla-nss-certs-32bit-debuginfo
mozilla-nspr-debuginfo-32bit
mozilla-nspr-32bit
mozilla-nspr-devel
mozilla-nspr-debugsource
mozilla-nspr-debuginfo
mozilla-nspr
mozilla-nspr-64bit
mozilla-nspr-32bit-debuginfo
mozilla-nspr-64bit-debuginfo
MozillaFirefox-debuginfo
MozillaFirefox-translations-common
MozillaFirefox-debugsource
MozillaFirefox
MozillaFirefox-devel
MozillaFirefox-translations-other
MozillaFirefox-branding-upstream
MozillaFirefox-branding-SLE

Install security update from vendor's website.

Firefox for Android - update to 154.0
Mozilla Firefox - update to 154.0
Firefox ESR - update to 153.1.0
Mozilla Thunderbird - addressed in versions 153.1.0, 154.0
rust-cbindgen-debugsource - update to 0.29.4+git0-150400.11.3.2
rust-cbindgen - update to 0.29.4+git0-150400.11.3.2
rust-cbindgen-debuginfo - update to 0.29.4+git0-150400.11.3.2
libsoftokn3-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss-certs-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-debuginfo - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-certs-debuginfo-32bit - update to 3.125-58.147.1
libsoftokn3-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libfreebl3-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss-tools-debuginfo - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libfreebl3 - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-sysinit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss-sysinit-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-sysinit-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss-tools - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-sysinit-debuginfo - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libsoftokn3-debuginfo - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-certs - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libfreebl3-debuginfo - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-certs-debuginfo - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libsoftokn3 - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-debugsource - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-devel - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libfreebl3-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-32bit-debuginfo - update to 3.125-150400.3.74.1
libfreebl3-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-sysinit-32bit-debuginfo - update to 3.125-150400.3.74.1
libsoftokn3-64bit - update to 3.125-150400.3.74.1
mozilla-nss-certs-64bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-sysinit-64bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-certs-64bit - update to 3.125-150400.3.74.1
mozilla-nss-sysinit-64bit - update to 3.125-150400.3.74.1
libsoftokn3-64bit-debuginfo - update to 3.125-150400.3.74.1
libfreebl3-64bit-debuginfo - update to 3.125-150400.3.74.1
libfreebl3-64bit - update to 3.125-150400.3.74.1
mozilla-nss-64bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-64bit - update to 3.125-150400.3.74.1
libsoftokn3-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-certs-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nspr-debuginfo-32bit - update to 4.39-19.39.1
mozilla-nspr-32bit - addressed in versions 4.39-19.39.1, 4.39-150400.12.3.1
mozilla-nspr-devel - addressed in versions 4.39-19.39.1, 4.39-150400.12.3.1
mozilla-nspr-debugsource - addressed in versions 4.39-19.39.1, 4.39-150400.12.3.1
mozilla-nspr-debuginfo - addressed in versions 4.39-19.39.1, 4.39-150400.12.3.1
mozilla-nspr - addressed in versions 4.39-19.39.1, 4.39-150400.12.3.1
mozilla-nspr-64bit - update to 4.39-150400.12.3.1
mozilla-nspr-32bit-debuginfo - update to 4.39-150400.12.3.1
mozilla-nspr-64bit-debuginfo - update to 4.39-150400.12.3.1
MozillaFirefox-debuginfo - addressed in versions 140.14.0-112.327.1, 140.14.0-150200.152.251.1, 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-translations-common - addressed in versions 140.14.0-112.327.1, 140.14.0-150200.152.251.1, 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-debugsource - addressed in versions 140.14.0-112.327.1, 140.14.0-150200.152.251.1, 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox - addressed in versions 140.14.0-112.327.1, 140.14.0-150200.152.251.1, 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-devel - addressed in versions 140.14.0-112.327.1, 140.14.0-150200.152.251.1, 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-translations-other - addressed in versions 140.14.0-150200.152.251.1, 153.2.0-150400.157.5.1
MozillaFirefox-branding-upstream - update to 153.2.0-150400.157.5.1
MozillaFirefox-branding-SLE - addressed in versions 153-41.3.8, 153-150400.14.3.1

• https://www.mozilla.org/en-US/security/advisories/mfsa2026-77/
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-74/
• https://bugzilla.mozilla.org/show_bug.cgi?id=2045676

• Multiple vulnerabilities in Mozilla Firefox and Firefox ESR
• Multiple vulnerabilities in Mozilla Thunderbird ESR 153
• Multiple vulnerabilities in Mozilla Thunderbird
• SUSE update for MozillaFirefox
• SUSE update for MozillaFirefox
• SUSE update for MozillaFirefox, MozillaFirefox-branding-SLE, mozilla-nspr, mozilla-nss, rust-cbindgen
• SUSE update for MozillaFirefox, mozilla-nspr, mozilla-nss, rust-cbindgen