Improper privilege management in Mozilla products - CVE-2026-16365

Vulnerability identifier: #VU138995

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-2026-16365

CWE-ID: CWE-269

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to escalate privileges.

The vulnerability exists due to improper access control in the DOM: Workers component when handling worker operations. A remote attacker can trigger crafted worker behavior to escalate privileges.

Firefox ESR
Mozilla Firefox
Firefox for Android
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
Debian Linux
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux Server - AUS
Desktop Applications Module
Basesystem Module
openSUSE Leap
openEuler
Anolis OS
Mozilla Thunderbird
rust-cbindgen-debuginfo
rust-cbindgen
rust-cbindgen-debugsource
mozilla-nss-certs
mozilla-nss-devel
mozilla-nss-tools
mozilla-nss-debugsource
libsoftokn3
mozilla-nss
mozilla-nss-certs-debuginfo
libfreebl3-32bit
mozilla-nss-sysinit-debuginfo
mozilla-nss-sysinit
libfreebl3-debuginfo-32bit
mozilla-nss-debuginfo
mozilla-nss-sysinit-32bit
mozilla-nss-tools-debuginfo
libfreebl3
libsoftokn3-debuginfo
mozilla-nss-debuginfo-32bit
libsoftokn3-32bit
mozilla-nss-certs-32bit
mozilla-nss-certs-debuginfo-32bit
libsoftokn3-debuginfo-32bit
mozilla-nss-32bit
mozilla-nss-sysinit-debuginfo-32bit
libfreebl3-debuginfo
libfreebl3-32bit-debuginfo
mozilla-nss-32bit-debuginfo
libsoftokn3-32bit-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
mozilla-nss-certs-32bit-debuginfo
mozilla-nspr-32bit
mozilla-nspr-debuginfo-32bit
mozilla-nspr
mozilla-nspr-debugsource
mozilla-nspr-debuginfo
mozilla-nspr-devel
mozilla-nspr-32bit-debuginfo
mozilla-nspr-64bit-debuginfo
mozilla-nspr-64bit
firefox-debugsource
firefox-debuginfo
firefox
firefox-esr (Debian package)
firefox (Red Hat package)
MozillaFirefox
MozillaFirefox-debugsource
MozillaFirefox-debuginfo
MozillaFirefox-devel
MozillaFirefox-translations-common
MozillaFirefox-translations-other
MozillaFirefox-branding-upstream
MozillaFirefox-branding-SLE

Install security update from vendor's website.

Firefox ESR - addressed in versions 140.15.0, 153.2.0
Firefox for Android - update to 153.0
Mozilla Firefox - update to 153.0
Mozilla Thunderbird - update to 153.0
rust-cbindgen-debuginfo - update to 0.29.4+git0-150400.11.3.2
rust-cbindgen - 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-certs - 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
mozilla-nss-debugsource - 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 - 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
libfreebl3-32bit - 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
libfreebl3-debuginfo-32bit - update to 3.125-58.147.1
mozilla-nss-debuginfo - 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-tools-debuginfo - 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
libsoftokn3-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
libsoftokn3-32bit - 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-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-debuginfo-32bit - update to 3.125-58.147.1
libfreebl3-debuginfo - addressed in versions 3.125-58.147.1, 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
libsoftokn3-32bit-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
mozilla-nss-certs-32bit-debuginfo - 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 - 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-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
firefox-esr (Debian package) - update to 140.15.0esr-1~deb13u1
firefox (Red Hat package) - addressed in versions 140.15.0-1.el8_4, 140.15.0-1.el8_10, 140.15.0-1.el9_8, 140.15.0-1.el10_2
firefox - update to 140.16.0-1
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-debuginfo - addressed in versions 153.2.0-118.5.4, 153.2.0-150400.157.5.1
MozillaFirefox-devel - 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-translations-other - update to 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/mfsa2026-68/
• https://bugzilla.mozilla.org/show_bug.cgi?id=2049149
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-84/

• Multiple vulnerabilities in Mozilla Firefox
• Multiple vulnerabilities in Mozilla Thunderbird
• 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
• Red Hat Enterprise Linux 8 update for firefox
• Anolis OS update for firefox