Buffer overflow in Mozilla products - CVE-2026-6785

Vulnerability identifier: #VU126661

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-2026-6785

CWE-ID: CWE-119

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 memory corruption in multiple components when rendering crafted web content. A remote attacker can cause the browser to process specially crafted content to execute arbitrary code.

The advisory states that some of the underlying bugs showed evidence of memory corruption.

Mozilla Firefox
Firefox ESR
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
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 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 Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
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
Anolis OS
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
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 IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
SUSE Package Hub 15
Desktop Applications Module
openEuler
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
firefox-esr (Debian package)
thunderbird (Debian package)
firefox-debuginfo
firefox-debugsource
firefox
thunderbird
thunderbird-debuginfo
thunderbird-debugsource
thunderbird-librnp-rnp
thunderbird-wayland
firefox (Red Hat package)
thunderbird (Red Hat package)
MozillaFirefox-devel
MozillaFirefox-debuginfo
MozillaFirefox
MozillaFirefox-translations-common
MozillaFirefox-debugsource
MozillaFirefox-translations-other
MozillaThunderbird
MozillaThunderbird-debuginfo
MozillaThunderbird-debugsource
MozillaThunderbird-translations-other
MozillaThunderbird-translations-common
Mozilla Thunderbird

Install security update from vendor's website.

Mozilla Firefox - update to 150.0
Firefox for Android - update to 150.0
Firefox ESR - addressed in versions 115.35.0, 140.10.0
Mozilla Thunderbird - addressed in versions 140.10.0, 150.0
firefox-esr (Debian package) - addressed in versions 140.10.0esr-1~deb12u1, 140.10.0esr-1~deb13u1
thunderbird (Debian package) - addressed in versions 1:140.10.0esr-1~deb12u1, 1:140.10.0esr-1~deb13u1
firefox-debuginfo - update to 140.10.0-1
firefox-debugsource - update to 140.10.0-1
firefox - update to 140.10.0-1
thunderbird - update to 140.10.0-1
thunderbird-debuginfo - update to 140.10.0-1
thunderbird-debugsource - update to 140.10.0-1
thunderbird-librnp-rnp - update to 140.10.0-1
thunderbird-wayland - update to 140.10.0-1
firefox (Red Hat package) - addressed in versions 140.10.0-1.el8_4, 140.10.0-1.el8_6, 140.10.0-1.el8_8, 140.10.0-1.el8_10, 140.10.0-1.el9_0, 140.10.0-1.el9_2, 140.10.0-1.el9_7, 140.10.0-1.el10_0, 140.10.0-1.el10_1, 140.10.0-2.el7_9
thunderbird (Red Hat package) - addressed in versions 140.10.0-1.el8_4, 140.10.0-1.el8_8, 140.10.0-1.el8_10, 140.10.0-1.el9_2, 140.10.0-1.el9_6, 140.10.0-1.el9_7, 140.10.0-1.el10_1
firefox - update to 140.10.0-1.0.1
MozillaFirefox-devel - addressed in versions 140.10.0-112.310.1, 140.10.0-150200.152.231.1
MozillaFirefox-debuginfo - addressed in versions 140.10.0-112.310.1, 140.10.0-150200.152.231.1
MozillaFirefox - addressed in versions 140.10.0-112.310.1, 140.10.0-150200.152.231.1
MozillaFirefox-translations-common - addressed in versions 140.10.0-112.310.1, 140.10.0-150200.152.231.1
MozillaFirefox-debugsource - addressed in versions 140.10.0-112.310.1, 140.10.0-150200.152.231.1
MozillaFirefox-translations-other - update to 140.10.0-150200.152.231.1
MozillaThunderbird - update to 140.10.1-150200.8.271.1
MozillaThunderbird-debuginfo - update to 140.10.1-150200.8.271.1
MozillaThunderbird-debugsource - update to 140.10.1-150200.8.271.1
MozillaThunderbird-translations-other - update to 140.10.1-150200.8.271.1
MozillaThunderbird-translations-common - update to 140.10.1-150200.8.271.1
thunderbird - update to 140.12.0-1.0.1

• https://www.mozilla.org/en-US/security/advisories/mfsa2026-31/
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-30/
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-32/
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1935995 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1999158 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2015952 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2021909 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022026 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022041 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022088 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022276 
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022335
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022338
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022373
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022597
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022874
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2023276
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2023544
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2023551
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2023599
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2023608
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2023814
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024233
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024239
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024241
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024242
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024250
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024251
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024343
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024422
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024425
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024440
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024442
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024446
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024458
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024463
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024478
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024650
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024653
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024654
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024655
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024656
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024661
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024662
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024668
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2024919
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025278
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025349
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025350
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025354
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025360
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025363
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025370
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025379
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025381
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025399
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025400
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025403
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025407
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025415
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025420
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025427
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025429
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025430
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025479
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025489
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025493
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025497
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025502
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025515
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025517
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025526
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025609
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025948
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025949
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025951
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025953
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025955
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025962
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025969
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025970
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025971
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025973
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025976
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025977
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2026280
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2026285
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2026293
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2026296
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2026310
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027237
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027260
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027268
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027277
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027284
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027291
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027293
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027298
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027330
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027342
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027345
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027359
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027365
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027378
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027754
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027959
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027962
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027964
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027971
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027974
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027979
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027982
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027995
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028001
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028267
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028268
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028275
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028288
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028290
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028291
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028528
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028551
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028627
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028879
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2028889
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029061
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029071
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029283
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029296
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029314
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029323
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029411
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029423
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029424
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029425
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029427
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029436
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029440
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029449
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029450
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029458
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029462
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029468
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029472
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029690
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029707
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029708
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029728
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029802
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029896
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2029906
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2030106
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2030118
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2030123
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2030135
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2030230
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2030320

• Multiple vulnerabilities in Mozilla Firefox
• Multiple vulnerabilities in Mozilla Thunderbird ESR
• Multiple vulnerabilities in Mozilla Thunderbird
• openEuler 24.03 LTS SP3 update for thunderbird
• openEuler 24.03 LTS SP3 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
• Red Hat Enterprise Linux 9 update for firefox
• Red Hat Enterprise Linux 8 update for firefox
• Red Hat Enterprise Linux 10 update for firefox
• SUSE update for MozillaFirefox
• SUSE update for MozillaFirefox
• Red Hat Enterprise Linux 10 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• SUSE update for MozillaThunderbird
• Anolis OS update for firefox
• Red Hat Enterprise Linux 9 update for thunderbird
• Debian update for thunderbird
• Debian update for firefox-esr
• 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 10 update for firefox
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 9 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 8 update for firefox
• Red Hat Enterprise Linux 8 update for firefox
• Red Hat Enterprise Linux 7 Extended Lifecycle Support update for firefox
• Anolis OS update for thunderbird