Integer overflow in Mozilla products - CVE-2026-2781

Vulnerability identifier: #VU123207

CSH Severity: Low

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

CVE-ID: CVE-2026-2781

CWE-ID: CWE-190

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to crash the browser.

The vulnerability exists due to integer overflow in the Libraries component in NSS. A remote attacker can trick the victim into visiting a specially crafted website, trigger an integer overflow and crash the browser.

Firefox ESR
Mozilla Firefox
Firefox for Android
Debian Linux
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server for SAP Applications 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 15
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Micro
SUSE Linux Enterprise Micro for Rancher
Anolis OS
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Ubuntu
Desktop Applications Module
SUSE Package Hub 15
Basesystem Module
openSUSE Leap
openEuler
Fedora
Mozilla NSS
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
nss (Ubuntu package)
nss (Debian package)
nss-doc
nss
nss-devel
nss-pkcs11-devel
nss-softokn-devel
nss-softokn-freebl
nss-softokn-freebl-devel
nss-sysinit
nss-tools
nss-util
nss-util-devel
nss-softokn
mozilla-nss-devel
mozilla-nss-sysinit-debuginfo
mozilla-nss
libfreebl3-debuginfo
mozilla-nss-debugsource
libsoftokn3
mozilla-nss-sysinit
libfreebl3
libsoftokn3-debuginfo
mozilla-nss-tools
mozilla-nss-certs
mozilla-nss-certs-debuginfo
mozilla-nss-tools-debuginfo
mozilla-nss-debuginfo
mozilla-nss-certs-32bit
mozilla-nss-sysinit-debuginfo-32bit
mozilla-nss-certs-debuginfo-32bit
mozilla-nss-32bit
libfreebl3-32bit
mozilla-nss-debuginfo-32bit
libfreebl3-debuginfo-32bit
libsoftokn3-32bit
mozilla-nss-sysinit-32bit
libsoftokn3-debuginfo-32bit
libsoftokn3-32bit-debuginfo
mozilla-nss-32bit-debuginfo
mozilla-nss-sysinit-32bit-debuginfo
mozilla-nss-64bit-debuginfo
libfreebl3-64bit-debuginfo
mozilla-nss-certs-64bit
mozilla-nss-64bit
libsoftokn3-64bit-debuginfo
mozilla-nss-sysinit-64bit
mozilla-nss-certs-64bit-debuginfo
mozilla-nss-sysinit-64bit-debuginfo
libsoftokn3-64bit
libfreebl3-64bit
mozilla-nss-certs-32bit-debuginfo
libfreebl3-32bit-debuginfo
firefox-esr (Debian package)
thunderbird (Debian package)
firefox-debuginfo
thunderbird
firefox
thunderbird-debuginfo
thunderbird-debugsource
thunderbird-librnp-rnp
thunderbird-wayland
firefox-debugsource
thunderbird (Red Hat package)
firefox (Red Hat package)
MozillaFirefox-debuginfo
MozillaFirefox
MozillaFirefox-translations-common
MozillaFirefox-debugsource
MozillaFirefox-devel
MozillaThunderbird-translations-other
MozillaThunderbird-debuginfo
MozillaThunderbird-translations-common
MozillaThunderbird
MozillaThunderbird-debugsource
MozillaFirefox-translations-other
MozillaFirefox-branding-upstream
Mozilla Thunderbird

Install updates from vendor's website.

Firefox ESR - addressed in versions 115.35.0, 140.8.0
Mozilla Firefox - update to 148.0
Firefox for Android - update to 148.0
Mozilla NSS - addressed in versions 3.112.3, 3.120.1, 3.121
Mozilla Thunderbird - addressed in versions 140.8.0, 148.0
nss (Ubuntu package) - addressed in versions 2:3.28.4-0ubuntu0.14.04.5+esm13, 2:3.28.4-0ubuntu0.16.04.14+esm5, 2:3.35-2ubuntu2.16+esm1, 2:3.98-0ubuntu0.20.04.2+esm1, 2:3.98-0ubuntu0.22.04.3, 2:3.98-1ubuntu0.1, 2:3.114-1ubuntu0.1
nss (Debian package) - addressed in versions 2:3.87.1-1+deb12u2, 2:3.110-1+deb13u1
nss-doc - update to 3.112-2
nss - update to 3.112-2
nss-devel - update to 3.112-2
nss-pkcs11-devel - update to 3.112-2
nss-softokn-devel - update to 3.112-2
nss-softokn-freebl - update to 3.112-2
nss-softokn-freebl-devel - update to 3.112-2
nss-sysinit - update to 3.112-2
nss-tools - update to 3.112-2
nss-util - update to 3.112-2
nss-util-devel - update to 3.112-2
nss-softokn - update to 3.112-2
mozilla-nss-devel - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
mozilla-nss-sysinit-debuginfo - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
mozilla-nss - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
libfreebl3-debuginfo - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-debugsource - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
libsoftokn3 - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-sysinit - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
libfreebl3 - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
libsoftokn3-debuginfo - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-tools - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-certs - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-certs-debuginfo - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-tools-debuginfo - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-debuginfo - addressed in versions 3.112.3-58.136.1, 3.112.3-150000.3.135.1, 3.112.3-150400.3.63.1
mozilla-nss-certs-32bit - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
mozilla-nss-sysinit-debuginfo-32bit - update to 3.112.3-58.136.1
mozilla-nss-certs-debuginfo-32bit - update to 3.112.3-58.136.1
mozilla-nss-32bit - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
libfreebl3-32bit - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
mozilla-nss-debuginfo-32bit - update to 3.112.3-58.136.1
libfreebl3-debuginfo-32bit - update to 3.112.3-58.136.1
libsoftokn3-32bit - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
mozilla-nss-sysinit-32bit - addressed in versions 3.112.3-58.136.1, 3.112.3-150400.3.63.1
libsoftokn3-debuginfo-32bit - update to 3.112.3-58.136.1
libsoftokn3-32bit-debuginfo - update to 3.112.3-150400.3.63.1
mozilla-nss-32bit-debuginfo - update to 3.112.3-150400.3.63.1
mozilla-nss-sysinit-32bit-debuginfo - update to 3.112.3-150400.3.63.1
mozilla-nss-64bit-debuginfo - update to 3.112.3-150400.3.63.1
libfreebl3-64bit-debuginfo - update to 3.112.3-150400.3.63.1
mozilla-nss-certs-64bit - update to 3.112.3-150400.3.63.1
mozilla-nss-64bit - update to 3.112.3-150400.3.63.1
libsoftokn3-64bit-debuginfo - update to 3.112.3-150400.3.63.1
mozilla-nss-sysinit-64bit - update to 3.112.3-150400.3.63.1
mozilla-nss-certs-64bit-debuginfo - update to 3.112.3-150400.3.63.1
mozilla-nss-sysinit-64bit-debuginfo - update to 3.112.3-150400.3.63.1
libsoftokn3-64bit - update to 3.112.3-150400.3.63.1
libfreebl3-64bit - update to 3.112.3-150400.3.63.1
mozilla-nss-certs-32bit-debuginfo - update to 3.112.3-150400.3.63.1
libfreebl3-32bit-debuginfo - update to 3.112.3-150400.3.63.1
nss - update to 3.121.0-1.fc44
firefox-esr (Debian package) - addressed in versions 140.8.0esr-1~deb12u1, 140.8.0esr-1~deb13u1
thunderbird (Debian package) - addressed in versions 1:140.8.0esr-1~deb12u1, 1:140.8.0esr-1~deb13u1
firefox-debuginfo - update to 140.8.0-1
thunderbird - update to 140.8.0-1
firefox - update to 140.8.0-1
thunderbird-debuginfo - update to 140.8.0-1
thunderbird-debugsource - update to 140.8.0-1
thunderbird-librnp-rnp - update to 140.8.0-1
thunderbird-wayland - update to 140.8.0-1
firefox-debugsource - update to 140.8.0-1
thunderbird (Red Hat package) - addressed in versions 140.8.0-1.el8_2, 140.8.0-1.el8_6, 140.8.0-1.el8_8, 140.8.0-1.el9_0, 140.8.0-1.el9_2, 140.8.0-1.el9_6, 140.8.0-1.el9_7, 140.8.0-2.el10_0, 140.8.0-2.el10_1
firefox (Red Hat package) - addressed in versions 140.8.0-2.el7_9, 140.8.0-2.el8_2, 140.8.0-2.el8_4, 140.8.0-2.el8_6, 140.8.0-2.el8_8, 140.8.0-2.el9_0, 140.8.0-2.el9_2, 140.8.0-2.el9_4, 140.8.0-2.el9_6, 140.8.0-2.el9_7, 140.8.0-2.el10_1
firefox - update to 140.8.0-2.0.1
MozillaFirefox-debuginfo - addressed in versions 140.8.0-112.301.1, 140.8.0-150200.152.222.1
MozillaFirefox - addressed in versions 140.8.0-112.301.1, 140.8.0-150200.152.222.1
MozillaFirefox-translations-common - addressed in versions 140.8.0-112.301.1, 140.8.0-150200.152.222.1
MozillaFirefox-debugsource - addressed in versions 140.8.0-112.301.1, 140.8.0-150200.152.222.1
MozillaFirefox-devel - addressed in versions 140.8.0-112.301.1, 140.8.0-150200.152.222.1
MozillaThunderbird-translations-other - update to 140.8.0-150200.8.260.1
MozillaThunderbird-debuginfo - update to 140.8.0-150200.8.260.1
MozillaThunderbird-translations-common - update to 140.8.0-150200.8.260.1
MozillaThunderbird - update to 140.8.0-150200.8.260.1
MozillaThunderbird-debugsource - update to 140.8.0-150200.8.260.1
MozillaFirefox-translations-other - update to 140.8.0-150200.152.222.1
MozillaFirefox-branding-upstream - update to 140.8.0-150200.152.222.1
thunderbird - update to 140.12.0-1.0.1

• https://www.mozilla.org/en-US/security/advisories/mfsa2026-15/
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-13/
• https://bugzilla.mozilla.org/show_bug.cgi?id=2009552
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-31/

• Multiple vulnerabilities in Mozilla Firefox
• Multiple vulnerabilities in Thunderbird ESR
• Multiple vulnerabilities in Mozilla Thunderbird
• Red Hat Enterprise Linux 9 update for firefox
• Red Hat Enterprise Linux 10 update for firefox
• Debian update for firefox-esr
• Debian update for nss
• Anolis OS update for firefox
• openEuler 24.03 LTS SP3 update for firefox
• openEuler 24.03 LTS SP2 update for firefox
• openEuler 24.03 LTS SP1 update for firefox
• openEuler 24.03 LTS update for firefox
• openEuler 22.03 LTS SP4 update for firefox
• Debian update for thunderbird
• Red Hat Enterprise Linux 8 update for firefox
• Red Hat Enterprise Linux 8 update for firefox
• Red Hat Enterprise Linux 9 update for firefox
• Red Hat Enterprise Linux 8 update for firefox
• Red Hat Enterprise Linux 8 update for firefox
• Red Hat Enterprise Linux 9 update for firefox
• Red Hat Enterprise Linux 9 update for firefox
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 10 update for thunderbird
• SUSE update for mozilla-nss
• Ubuntu update for nss
• SUSE update for MozillaFirefox
• SUSE update for mozilla-nss
• SUSE update for mozilla-nss
• Integer overflow in Mozilla NSS
• Fedora 44 update for nss
• Ubuntu update for nss
• openEuler 24.03 LTS SP3 update for thunderbird
• openEuler 24.03 LTS SP2 update for thunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 7 Extended Lifecycle Support update for firefox
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 9 update for firefox
• Red Hat Enterprise Linux 10 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• SUSE update for MozillaFirefox
• SUSE update for MozillaThunderbird
• Anolis OS update for nss
• Anolis OS update for thunderbird