Use-after-free in Mozilla products - CVE-2026-84118

Vulnerability identifier: #VU146614

CSH Severity: High

CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-84118

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to use-after-free in the JavaScript: GC component when processing crafted web content. A remote attacker can trigger garbage collection with crafted content to execute arbitrary code.

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

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

Install security update from vendor's website.

Firefox for Android - update to 155.0
Mozilla Firefox - update to 155.0
Firefox ESR - update to 153.2.0
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
mozilla-nss-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-certs-32bit - 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 - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libsoftokn3-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libsoftokn3-32bit - 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
mozilla-nss-sysinit - 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-debuginfo-32bit - update to 3.125-58.147.1
libfreebl3 - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libfreebl3-debuginfo-32bit - update to 3.125-58.147.1
libfreebl3-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-tools - 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-sysinit-32bit - 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
mozilla-nss-certs-debuginfo - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-tools-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-debugsource - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
libfreebl3-64bit - update to 3.125-150400.3.74.1
libfreebl3-64bit-debuginfo - update to 3.125-150400.3.74.1
libsoftokn3-64bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-sysinit-64bit - update to 3.125-150400.3.74.1
mozilla-nss-certs-64bit - 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-debuginfo - update to 3.125-150400.3.74.1
libsoftokn3-64bit - 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
mozilla-nss-sysinit-32bit-debuginfo - update to 3.125-150400.3.74.1
libfreebl3-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-certs-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-32bit-debuginfo - update to 3.125-150400.3.74.1
libsoftokn3-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nspr-debugsource - 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-debuginfo - addressed in versions 4.39-19.39.1, 4.39-150400.12.3.1
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-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-branding-SLE - addressed in versions 153-41.3.8, 153-150400.14.3.1
MozillaFirefox-devel - addressed in versions 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox - addressed in versions 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-debugsource - addressed in versions 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-translations-common - addressed in versions 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-debuginfo - addressed in versions 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-branding-upstream - update to 153.2.0-150400.157.5.1
MozillaFirefox-translations-other - update to 153.2.0-150400.157.5.1

• https://www.mozilla.org/en-US/security/advisories/mfsa2026-85/
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-82/
• https://bugzilla.mozilla.org/show_bug.cgi?id=2057457

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