Description
Memory safety bugs present in Firefox ESR 140.5, Thunderbird ESR 140.5, Firefox 145 and Thunderbird 145. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 146, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 140.6 |
| Mozilla | Thunderbird | — | 140.6 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | firefox-esr | 140.6.0esr-1 | — |
| Debian 14 | thunderbird | 1:140.6.0esr-1 | — |
| Debian 13 | firefox-esr | 140.6.0esr-1~deb13u1 | DSA-6078-1 |
| Debian 13 | thunderbird | 1:140.6.0esr-1~deb13u1 | DSA-6081-1 |
| Debian 12 | firefox-esr | 140.6.0esr-1~deb12u1 | DSA-6078-1 |
| Debian 12 | thunderbird | 1:140.6.0esr-1~deb12u1 | DSA-6081-1 |
| Debian 11 | firefox-esr | 140.6.0esr-1~deb11u1 | DLA-4401-1 |
| Debian 11 | thunderbird | 1:140.6.0esr-1~deb11u1 | DLA-4405-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | mozjs102 +1 | No fix yet | — |
| Ubuntu 22.04 LTS | mozjs78 +2 | No fix yet | — |
| Ubuntu 22.04 LTS | thunderbird | 1:140.7.1+build1-0ubuntu0.22.04.1 | — |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | firefox +1 | 140.6.0-1.el10_1 | RHSA-2026:0025, RHSA-2025:23035 |
| RHEL 9 | firefox +2 | 140.6.0-1.el9_7 | RHSA-2025:23856, RHSA-2025:23034 |
| RHEL 8 | firefox +1 | 140.6.0-1.el8_10 | RHSA-2026:0026, RHSA-2025:23128 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | firefox +1 | 140.6.0-1.el10_0 | RHSA-2026:0127, RHSA-2026:0124 |
| RHEL 9.6 EUS | firefox +1 | 140.6.0-2.el9_6 | RHSA-2026:0013 |
| RHEL 9.6 EUS | thunderbird | 140.6.0-1.el9_6 | RHSA-2026:0003 |
| RHEL 9.4 EUS | firefox +2 | 140.6.0-1.el9_4 | RHSA-2026:0016, RHSA-2026:0004 |
| RHEL 9.2 E4S | firefox +2 | 140.6.0-1.el9_2 | RHSA-2026:0019, RHSA-2026:0017 |
| RHEL 9.0 E4S | firefox +1 | 140.6.0-1.el9_0 | RHSA-2026:0020, RHSA-2026:0018 |
| RHEL 8.8 TUS | firefox | 140.6.0-2.el8_8 | RHSA-2026:0015 |
| RHEL 8.8 TUS | thunderbird | 140.6.0-1.el8_8 | RHSA-2026:0021 |
| RHEL 8.8 E4S | firefox | 140.6.0-2.el8_8 | RHSA-2026:0015 |
| RHEL 8.8 E4S | thunderbird | 140.6.0-1.el8_8 | RHSA-2026:0021 |
| RHEL 8.6 TUS | firefox | 140.6.0-2.el8_6 | RHSA-2026:0014 |
| RHEL 8.6 TUS | thunderbird | 140.6.0-1.el8_6 | RHSA-2026:0022 |
| RHEL 8.6 E4S | firefox | 140.6.0-2.el8_6 | RHSA-2026:0014 |
| RHEL 8.6 E4S | thunderbird | 140.6.0-1.el8_6 | RHSA-2026:0022 |
| RHEL 8.6 AUS | firefox | 140.6.0-2.el8_6 | RHSA-2026:0014 |
| RHEL 8.6 AUS | thunderbird | 140.6.0-1.el8_6 | RHSA-2026:0022 |
| RHEL 8.4 EUS Long Life | firefox | 140.6.0-2.el8_4 | RHSA-2026:0006 |
| RHEL 8.4 EUS Long Life | thunderbird | 140.6.0-1.el8_4 | RHSA-2026:0023 |
| RHEL 8.4 AUS | firefox | 140.6.0-2.el8_4 | RHSA-2026:0006 |
| RHEL 8.4 AUS | thunderbird | 140.6.0-1.el8_4 | RHSA-2026:0023 |
| RHEL 8.2 AUS | firefox +1 | 140.6.0-1.el8_2 | RHSA-2026:0024, RHSA-2026:0005 |
| RHEL 7 ELS | firefox | 140.6.0-1.el7_9 | RHSA-2026:0007 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | firefox | 140.6.0-1.el10_1 | ALSA-2025:23035 |
| AlmaLinux 10 | thunderbird | 140.6.0-1.el10_1.alma.1 | ALSA-2026:0025 |
| AlmaLinux 9 | firefox +2 | 140.6.0-1.el9_7.alma.1 | ALSA-2025:23856, ALSA-2025:23034 |
| AlmaLinux 8 | firefox +1 | 140.6.0-1.el8_10.alma.1 | ALSA-2026:0026, ALSA-2025:23128 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | firefox +1 | 140.6.0-1.el10_1 | RLSA-2026:0025, RLSA-2025:23035 |
| Rocky Linux 9 | firefox +1 | 140.6.0-1.el9_7 | RLSA-2025:23856, RLSA-2025:23034 |
| Rocky Linux 8 | firefox +1 | 140.6.0-1.el8_10 | RLSA-2026:0026, RLSA-2025:23128 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLES 15 SP7 | MozillaThunderbird | 140.6.0-150200.8.248.1 | SUSE-SU-2025:4397-1 |
| SLES 15 SP6 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLES 15 SP6 | MozillaThunderbird | 140.6.0-150200.8.248.1 | SUSE-SU-2025:4397-1 |
| SLES 15 SP5 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLES 15 SP4 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLES 15 SP3 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | MozillaFirefox | 140.6.0-112.292.1 | SUSE-SU-2025:4396-1 |
| SLES for SAP 16.0 | MozillaFirefox | 140.6.0-160000.1.1 | SUSE-SU-2026:20031-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLES 16.0 | MozillaFirefox | 140.6.0-160000.1.1 | SUSE-SU-2026:20031-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 146.0-1.1 | openSUSE-SU-2025:15813-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 140.6.0-1.1 | openSUSE-SU-2025:15814-1, openSUSE-SU-2025:15809-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 140.6.0-160000.1.1 | openSUSE-SU-2026:20014-1 |
| openSUSE Leap 16.0 | MozillaThunderbird | 140.6.0-bp160.1.1 | openSUSE-SU-2026:20046-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 140.6.0-150200.152.213.1 | SUSE-SU-2025:4424-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 140.6.0-150200.8.248.1 | SUSE-SU-2025:4397-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.6.0-1.amzn2023.0.1 | ALAS2023-2025-1337 |
| Amazon Linux 2 | thunderbird | 140.6.0-1.amzn2.0.1 | ALAS2-2025-3108 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox +1 | 140.6.0-1.0.1.el10_1 | ELSA-2026-0025, ELSA-2025-23035 |
| Oracle Linux 9 | firefox +2 | 140.6.0-1.0.1.el9_7 | ELSA-2025-23856, ELSA-2025-23034 |
| Oracle Linux 8 | firefox +1 | 140.6.0-1.0.1.el8_10 | ELSA-2026-0026, ELSA-2025-23128 |
| Oracle Linux 7 | firefox | 140.6.0-1.0.1.el7_9 | ELSA-2026-0007 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 140.6-r0 | — |
Advisories 50
- RHSA-2025:23034 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2025:23035 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- WID-SEC-2025-2812 Mozilla Firefox: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 5, 2026
- ALSA-2026:0025 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:23035 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:23856 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:23034 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:0026 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:23128 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-0489 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Oct 21, 2026
- RHSA-2026:0127 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0124 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0025 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0026 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0023 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0024 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0022 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0020 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0021 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0018 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0019 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0016 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0017 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0015 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0014 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0007 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0013 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0006 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0004 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0005 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0003 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2025:23856 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2025:23128 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- openSUSE-SU-2026:20046-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:20014-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15809-1 firefox-esr-140.6.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15813-1 MozillaFirefox-146.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15814-1 MozillaThunderbird-140.6.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20031-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4396-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4424-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4397-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 23, 2026
- ELSA-2026-0007 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jan 15, 2026
- ALAS2023-2025-1337 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jan 7, 2026
- ALAS2-2025-3108 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jan 5, 2026
- RLSA-2026:0026 Important: thunderbird security update Rocky Linux Security Advisories · Jan 5, 2026
- RLSA-2026:0025 Important: thunderbird security update Rocky Linux Security Advisories · Jan 5, 2026
- ELSA-2026-0026 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jan 5, 2026
- ELSA-2026-0025 Important: thunderbird security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jan 5, 2026
- RLSA-2025:23856 Important: thunderbird security update Rocky Linux Security Advisories · Dec 23, 2025
References
- Memory safety bugs fixed in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146
- https://www.mozilla.org/security/advisories/mfsa2025-92/
- https://www.mozilla.org/security/advisories/mfsa2025-94/
- https://www.mozilla.org/security/advisories/mfsa2025-95/
- https://www.mozilla.org/security/advisories/mfsa2025-96/