Improper access control in Mozilla products - CVE-2026-75874

Vulnerability identifier: #VU144097

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-75874

CWE-ID: CWE-284

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to escape the sandbox.

The vulnerability exists due to improper isolation in the Remote Settings Client component when handling remote settings data. A remote attacker can trigger the vulnerable component to escape the sandbox.

Mozilla Firefox
Firefox ESR
Firefox for Android
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
Debian Linux
SUSE Linux Enterprise High Performance Computing 15
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 Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Desktop Applications Module
Basesystem Module
openSUSE Leap
openEuler
Mozilla Thunderbird
rust-cbindgen
rust-cbindgen-debuginfo
rust-cbindgen-debugsource
mozilla-nss-sysinit
libsoftokn3-debuginfo
mozilla-nss-certs
libfreebl3-debuginfo
mozilla-nss-certs-debuginfo
mozilla-nss-debugsource
mozilla-nss-devel
mozilla-nss-tools
libfreebl3-32bit
libfreebl3-debuginfo-32bit
mozilla-nss-sysinit-debuginfo-32bit
mozilla-nss-32bit
mozilla-nss-sysinit-32bit
mozilla-nss-debuginfo
mozilla-nss-certs-32bit
mozilla-nss
mozilla-nss-sysinit-debuginfo
libsoftokn3-32bit
mozilla-nss-tools-debuginfo
mozilla-nss-certs-debuginfo-32bit
libsoftokn3
libsoftokn3-debuginfo-32bit
mozilla-nss-debuginfo-32bit
libfreebl3
mozilla-nss-64bit
mozilla-nss-sysinit-32bit-debuginfo
libsoftokn3-32bit-debuginfo
mozilla-nss-certs-32bit-debuginfo
libfreebl3-32bit-debuginfo
mozilla-nss-32bit-debuginfo
mozilla-nss-64bit-debuginfo
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-nspr-32bit
mozilla-nspr-debuginfo-32bit
mozilla-nspr-debugsource
mozilla-nspr
mozilla-nspr-debuginfo
mozilla-nspr-devel
mozilla-nspr-32bit-debuginfo
mozilla-nspr-64bit-debuginfo
mozilla-nspr-64bit
firefox-debugsource
firefox-debuginfo
firefox
MozillaFirefox-devel
MozillaFirefox
MozillaFirefox-debuginfo
MozillaFirefox-debugsource
MozillaFirefox-translations-common
MozillaFirefox-translations-other
firefox-esr (Debian package)
firefox (Red Hat package)
MozillaFirefox-branding-upstream
MozillaFirefox-branding-SLE

Install security update from vendor's website.

Mozilla Firefox - update to 154.0
Firefox for Android - update to 154.0
Firefox ESR - addressed in versions 115.40.0, 140.15.0, 153.2.0
Mozilla Thunderbird - update to 154.0
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
rust-cbindgen-debugsource - update to 0.29.4+git0-150400.11.3.2
mozilla-nss-sysinit - 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
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
mozilla-nss-tools - 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
libfreebl3-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss-sysinit-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss-32bit - addressed in versions 3.125-58.147.1, 3.125-150400.3.74.1
mozilla-nss-sysinit-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-32bit - 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
mozilla-nss-sysinit-debuginfo - 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-tools-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 - 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-debuginfo-32bit - update to 3.125-58.147.1
libfreebl3 - addressed in versions 3.125-58.147.1, 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
libsoftokn3-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-certs-32bit-debuginfo - update to 3.125-150400.3.74.1
libfreebl3-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-32bit-debuginfo - update to 3.125-150400.3.74.1
mozilla-nss-64bit-debuginfo - update to 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-nspr-32bit - 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-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-devel - addressed in versions 4.39-19.39.1, 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
mozilla-nspr-64bit - update to 4.39-150400.12.3.1
firefox-debugsource - addressed in versions 140.14.0-1, 140.15.0-1
firefox-debuginfo - addressed in versions 140.14.0-1, 140.15.0-1
firefox - addressed in versions 140.14.0-1, 140.15.0-1
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 - 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-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-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-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-translations-other - addressed in versions 140.14.0-150200.152.251.1, 153.2.0-150400.157.5.1
firefox-esr (Debian package) - update to 140.15.0esr-1~deb13u1
firefox (Red Hat package) - addressed in versions 140.15.0-1.el8_10, 140.15.0-1.el9_8, 140.15.0-1.el10_2
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/mfsa2026-74/
• https://bugzilla.mozilla.org/show_bug.cgi?id=2039972
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-83/
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-84/
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-85/

• Multiple vulnerabilities in Mozilla Firefox and Firefox ESR
• Multiple vulnerabilities in Mozilla Thunderbird
• SUSE update for MozillaFirefox
• SUSE update for MozillaFirefox
• Debian update for firefox-esr
• openEuler 22.03 LTS SP4 update for firefox
• openEuler 24.03 LTS SP4 update for firefox
• openEuler 24.03 LTS SP1 update for firefox
• Red Hat Enterprise Linux 10 update for firefox
• Red Hat Enterprise Linux 9 update for firefox
• Red Hat Enterprise Linux 8 update for firefox
• SUSE update for MozillaFirefox, MozillaFirefox-branding-SLE, mozilla-nspr, mozilla-nss, rust-cbindgen
• SUSE update for MozillaFirefox, mozilla-nspr, mozilla-nss, rust-cbindgen