Description
Memory safety bugs present in Firefox ESR 115.28, Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143. 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 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 115.29 |
| Mozilla | Thunderbird | — | 140.4 |
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 | 140.4.0esr-1 | — |
| Debian 14 | thunderbird | 1:140.4.0esr-1 | — |
| Debian 13 | firefox-esr | 140.4.0esr-1~deb13u1 | DSA-6025-1 |
| Debian 13 | thunderbird | 1:140.4.0esr-1~deb13u1 | DSA-6040-1 |
| Debian 12 | firefox-esr | 140.4.0esr-1~deb12u1 | DSA-6025-1 |
| Debian 12 | thunderbird | 1:140.4.0esr-1~deb12u1 | DSA-6040-1 |
| Debian 11 | firefox-esr | 140.4.0esr-1~deb11u1 | DLA-4335-1 |
| Debian 11 | thunderbird | 1:140.4.0esr-1~deb11u1 | DLA-4351-1 |
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 | 140.4.0-3.el10_0 | RHSA-2025:18154 |
| RHEL 10 | thunderbird | 140.4.0-2.el10_0 | RHSA-2025:18320 |
| RHEL 9 | firefox +1 | 140.4.0-3.el9_6 | RHSA-2025:18155 |
| RHEL 9 | thunderbird | 140.4.0-2.el9_6 | RHSA-2025:18321 |
| RHEL 8 | firefox | 140.4.0-3.el8_10 | RHSA-2025:18285 |
| RHEL 8 | thunderbird | 140.4.0-2.el8_10 | RHSA-2025:18983 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.4 EUS | firefox +1 | 140.4.0-3.el9_4 | RHSA-2025:21059 |
| RHEL 9.4 EUS | thunderbird | 140.4.0-2.el9_4 | RHSA-2025:19945 |
| RHEL 9.2 E4S | firefox +1 | 140.4.0-3.el9_2 | RHSA-2025:21064 |
| RHEL 9.2 E4S | thunderbird | 140.4.0-2.el9_2 | RHSA-2025:19944 |
| RHEL 9.0 E4S | firefox | 140.4.0-3.el9_0 | RHSA-2025:21058 |
| RHEL 9.0 E4S | thunderbird | 140.4.0-2.el9_0 | RHSA-2025:19943 |
| RHEL 8.8 TUS | firefox | 140.4.0-3.el8_8 | RHSA-2025:21057 |
| RHEL 8.8 TUS | thunderbird | 140.4.0-2.el8_8 | RHSA-2025:19942 |
| RHEL 8.8 E4S | firefox | 140.4.0-3.el8_8 | RHSA-2025:21057 |
| RHEL 8.8 E4S | thunderbird | 140.4.0-2.el8_8 | RHSA-2025:19942 |
| RHEL 8.6 TUS | firefox | 140.4.0-3.el8_6 | RHSA-2025:21056 |
| RHEL 8.6 TUS | thunderbird | 140.4.0-2.el8_6 | RHSA-2025:19941 |
| RHEL 8.6 E4S | firefox | 140.4.0-3.el8_6 | RHSA-2025:21056 |
| RHEL 8.6 E4S | thunderbird | 140.4.0-2.el8_6 | RHSA-2025:19941 |
| RHEL 8.6 AUS | firefox | 140.4.0-3.el8_6 | RHSA-2025:21056 |
| RHEL 8.6 AUS | thunderbird | 140.4.0-2.el8_6 | RHSA-2025:19941 |
| RHEL 8.4 EUS Long Life | firefox | 140.4.0-3.el8_4 | RHSA-2025:21055 |
| RHEL 8.4 EUS Long Life | thunderbird | 140.4.0-2.el8_4 | RHSA-2025:19939 |
| RHEL 8.4 AUS | firefox | 140.4.0-3.el8_4 | RHSA-2025:21055 |
| RHEL 8.4 AUS | thunderbird | 140.4.0-2.el8_4 | RHSA-2025:19939 |
| RHEL 8.2 AUS | firefox | 140.4.0-3.el8_2 | RHSA-2025:21054 |
| RHEL 8.2 AUS | thunderbird | 140.4.0-2.el8_2 | RHSA-2025:19938 |
| RHEL 7 ELS | firefox | 140.4.0-4.el7_9 | RHSA-2025:19278 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | firefox | 140.4.0-3.el10_0 | ALSA-2025:18154 |
| AlmaLinux 10 | thunderbird | 140.4.0-2.el10_0.alma.1 | ALSA-2025:18320 |
| AlmaLinux 9 | firefox +1 | 140.4.0-3.el9_6.alma.1 | ALSA-2025:18155 |
| AlmaLinux 9 | thunderbird | 140.4.0-2.el9_6.alma.1 | ALSA-2025:18321 |
| AlmaLinux 8 | firefox | 140.4.0-3.el8_10.alma.1 | ALSA-2025:18285 |
| AlmaLinux 8 | thunderbird | 140.4.0-2.el8_10.alma.1 | ALSA-2025:18983 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | firefox | 140.4.0-3.el10_0 | RLSA-2025:18154 |
| Rocky Linux 10 | thunderbird | 140.4.0-2.el10_0 | RLSA-2025:18320 |
| Rocky Linux 9 | firefox | 140.4.0-3.el9_6 | RLSA-2025:18155 |
| Rocky Linux 9 | thunderbird | 140.4.0-2.el9_6 | RLSA-2025:18321 |
| Rocky Linux 8 | firefox | 140.4.0-3.el8_10 | RLSA-2025:18285 |
| Rocky Linux 8 | thunderbird | 140.4.0-2.el8_10 | RLSA-2025:18983 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLES 15 SP7 | MozillaThunderbird | 140.4.0-150200.8.242.1 | SUSE-SU-2025:4006-1 |
| SLES 15 SP6 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLES 15 SP6 | MozillaThunderbird | 140.4.0-150200.8.242.1 | SUSE-SU-2025:4006-1 |
| SLES 15 SP5 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLES 15 SP4 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLES 15 SP3 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | MozillaFirefox | 140.4.0-112.286.1 | SUSE-SU-2025:4174-1, SUSE-SU-2025:3808-1 |
| SLES for SAP 16.0 | MozillaFirefox | 140.5.0-160000.1.1 | SUSE-SU-2025:21021-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLES 16.0 | MozillaFirefox | 140.5.0-160000.1.1 | SUSE-SU-2025:21021-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 144.0-1.1 | openSUSE-SU-2025:15645-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 140.4.0-1.1 | openSUSE-SU-2025:15646-1, openSUSE-SU-2025:15632-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 140.5.0-160000.1.1 | openSUSE-SU-2025:20065-1 |
| openSUSE Leap 16.0 | MozillaThunderbird | 140.4.0-bp160.1.1 | openSUSE-SU-2025:20026-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 140.4.0-150200.152.207.1 | SUSE-SU-2025:4173-1, SUSE-SU-2025:3775-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 140.4.0-150200.8.242.1 | SUSE-SU-2025:4006-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.4.0-1.amzn2023.0.2 | ALAS2023-2025-1246 |
| Amazon Linux 2 | thunderbird | 140.4.0-1.amzn2.0.1 | ALAS2-2025-3052 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox | 140.4.0-3.0.1.el10_0 | ELSA-2025-18154 |
| Oracle Linux 10 | thunderbird | 140.4.0-2.0.1.el10_0 | ELSA-2025-18320 |
| Oracle Linux 9 | firefox +1 | 140.4.0-3.0.1.el9_6 | ELSA-2025-18155 |
| Oracle Linux 9 | thunderbird | 140.4.0-2.0.1.el9_6 | ELSA-2025-18321 |
| Oracle Linux 8 | firefox | 140.4.0-3.0.1.el8_10 | ELSA-2025-18285 |
| Oracle Linux 8 | thunderbird | 140.4.0-2.0.1.el8_10 | ELSA-2025-18983 |
| Oracle Linux 7 | firefox | 140.4.0-4.0.1.el7_9 | ELSA-2025-19278 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 140.4-r0 | — |
Advisories 50
- ALSA-2025:18154 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:18320 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:18321 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:18155 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:18983 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:18285 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2025-2275 Mozilla Firefox: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 30, 2026
- RHSA-2025:19944 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:21059 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:19278 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:18285 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:21064 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:21058 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:21056 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:21057 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:21055 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:21054 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:19945 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:19942 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:19943 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:19939 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:19941 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:19938 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:18983 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:18321 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:18320 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:18154 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- RHSA-2025:18155 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 30, 2026
- openSUSE-SU-2025:20065-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:20026-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15646-1 MozillaThunderbird-140.4.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15645-1 MozillaFirefox-144.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15632-1 firefox-esr-140.4.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4006-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:3808-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21021-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- RLSA-2025:18285 Important: firefox security update Rocky Linux Security Advisories · Feb 7, 2026
- SUSE-SU-2025:4174-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:3775-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4173-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2025-19278 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Dec 15, 2025
- RLSA-2025:18321 Important: thunderbird security update Rocky Linux Security Advisories · Oct 28, 2025
- ALAS2-2025-3052 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 27, 2025
- ALAS2023-2025-1246 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 27, 2025
- DLA-4351-1 thunderbird - security update Debian Security (DSA / DLA) · Oct 27, 2025
- DSA-6040-1 thunderbird - security update Debian Security (DSA / DLA) · Oct 26, 2025
- RLSA-2025:18320 Important: thunderbird security update Rocky Linux Security Advisories · Oct 26, 2025
- RLSA-2025:18983 Important: thunderbird security update Rocky Linux Security Advisories · Oct 23, 2025
- ELSA-2025-18983 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Oct 23, 2025
- NCSC-2025-0325 Kwetsbaarheden verholpen in Mozilla Firefox en Thunderbird NCSC-NL (Netherlands) · Oct 20, 2025
References
- Memory safety bugs fixed in Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird ESR 140.4, Firefox 144 and Thunderbird 144
- https://www.mozilla.org/security/advisories/mfsa2025-81/
- https://www.mozilla.org/security/advisories/mfsa2025-82/
- https://www.mozilla.org/security/advisories/mfsa2025-83/
- https://www.mozilla.org/security/advisories/mfsa2025-84/
- https://www.mozilla.org/security/advisories/mfsa2025-85/