Description
Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6. 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 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 128.7 |
| Mozilla | Thunderbird | — | 128.7 |
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 | 128.7.0esr-1 | — |
| Debian 14 | thunderbird | 1:128.7.0esr-1 | — |
| Debian 13 | firefox-esr | 128.7.0esr-1 | — |
| Debian 13 | thunderbird | 1:128.7.0esr-1 | — |
| Debian 12 | firefox-esr | 128.7.0esr-1~deb12u1 | DSA-5858-1 |
| Debian 12 | thunderbird | 1:128.7.0esr-1~deb12u1 | DSA-5861-1 |
| Debian 11 | firefox-esr | 128.7.0esr-1~deb11u1 | DLA-4044-1 |
| Debian 11 | thunderbird | 1:128.7.0esr-1~deb11u1 | DLA-4045-1 |
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 | 1:128.12.0+build1-0ubuntu0.22.04.1 | USN-7663-1 |
| Ubuntu 20.04 LTS | firefox | 135.0+build2-0ubuntu0.20.04.1 | USN-7263-1 |
| 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 9 | firefox +2 | 128.7.0-1.el9_5 | RHSA-2025:1184, RHSA-2025:1066 |
| RHEL 8 | firefox +1 | 128.7.0-1.el8_10 | RHSA-2025:1292, RHSA-2025:1283 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.4 EUS | firefox +2 | 128.7.0-1.el9_4 | RHSA-2025:1318, RHSA-2025:1140 |
| RHEL 9.2 EUS | firefox +2 | 128.7.0-1.el9_2 | RHSA-2025:1317, RHSA-2025:1139 |
| RHEL 9.0 E4S | firefox +1 | 128.7.0-1.el9_0 | RHSA-2025:1319, RHSA-2025:1138 |
| RHEL 8.8 EUS | firefox +1 | 128.7.0-1.el8_8 | RHSA-2025:1340, RHSA-2025:1137 |
| RHEL 8.6 TUS | firefox +1 | 128.7.0-1.el8_6 | RHSA-2025:1341, RHSA-2025:1136 |
| RHEL 8.6 E4S | firefox +1 | 128.7.0-1.el8_6 | RHSA-2025:1341, RHSA-2025:1136 |
| RHEL 8.6 AUS | firefox +1 | 128.7.0-1.el8_6 | RHSA-2025:1341, RHSA-2025:1136 |
| RHEL 8.4 TUS | firefox +1 | 128.7.0-1.el8_4 | RHSA-2025:1339, RHSA-2025:1135 |
| RHEL 8.4 E4S | firefox +1 | 128.7.0-1.el8_4 | RHSA-2025:1339, RHSA-2025:1135 |
| RHEL 8.4 AUS | firefox +1 | 128.7.0-1.el8_4 | RHSA-2025:1339, RHSA-2025:1135 |
| RHEL 8.2 AUS | firefox +1 | 128.7.0-1.el8_2 | RHSA-2025:1348, RHSA-2025:1133 |
| RHEL 7 ELS | firefox | 128.7.0-1.el7_9 | RHSA-2025:1132 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | firefox +1 | 128.7.0-1.el9_5 | ALSA-2025:1066 |
| AlmaLinux 9 | thunderbird | 128.7.0-1.el9_5.alma.1 | ALSA-2025:1184 |
| AlmaLinux 8 | firefox | 128.7.0-1.el8_10 | ALSA-2025:1283 |
| AlmaLinux 8 | thunderbird | 128.7.0-1.el8_10.alma.1 | ALSA-2025:1292 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox +1 | 128.7.0-1.el8_10 | RLSA-2025:1292, RLSA-2025:1283 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLES 15 SP6 | MozillaThunderbird | 128.7.0-150200.8.200.1 | SUSE-SU-2025:0405-1 |
| SLES 15 SP5 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLES 15 SP4 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLES 15 SP3 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLES 12 SP5 | MozillaFirefox | 128.7.0-112.246.1 | SUSE-SU-2025:0391-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP5 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 135.0-1.1 | openSUSE-SU-2025:14730-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 128.7.0-1.1 | openSUSE-SU-2025:14731-1, openSUSE-SU-2025:14727-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 128.7.0-150200.152.170.1 | SUSE-SU-2025:0374-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 128.7.0-150200.8.200.1 | SUSE-SU-2025:0405-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 128.7.0-1.amzn2.0.2 | ALAS2-2025-2789 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | firefox +2 | 128.7.0-1.0.1.el9_5 | ELSA-2025-1184, ELSA-2025-1066 |
| Oracle Linux 8 | firefox +1 | 128.7.0-1.0.1.el8_10 | ELSA-2025-1292, ELSA-2025-1283 |
| Oracle Linux 7 | firefox | 128.7.0-1.0.1.el7_9 | ELSA-2025-1132 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 135.0-r0 | — |
Advisories 45
- ALSA-2025:1184 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:1066 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:1283 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:1292 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- USN-7663-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-7263-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- RHSA-2025:1341 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1348 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1339 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1340 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1319 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1317 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1318 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1292 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1283 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1184 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1140 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1138 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1139 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1136 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1137 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1135 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1132 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1133 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:1066 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- DSA-5858-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-5861-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4045-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4044-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2025:1292 Important: thunderbird security update Rocky Linux Security Advisories · Feb 4, 2026
- RLSA-2025:1283 Important: firefox security update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2025:0405-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14731-1 MozillaThunderbird-128.7.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14730-1 MozillaFirefox-135.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:0374-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14727-1 firefox-esr-128.7.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:0391-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-0262 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 2, 2026
- ALAS2-2025-2789 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Mar 7, 2025
- ELSA-2025-1132 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 12, 2025
- ELSA-2025-1292 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 11, 2025
- ELSA-2025-1283 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 11, 2025
- ELSA-2025-1184 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Feb 10, 2025
- NCSC-2025-0040 Kwetsbaarheden verholpen in Mozilla Firefox en Thunderbird NCSC-NL (Netherlands) · Feb 7, 2025
- ELSA-2025-1066 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Feb 5, 2025
References
- Memory safety bugs fixed in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7
- https://www.mozilla.org/security/advisories/mfsa2025-07/
- https://www.mozilla.org/security/advisories/mfsa2025-09/
- https://www.mozilla.org/security/advisories/mfsa2025-10/
- https://www.mozilla.org/security/advisories/mfsa2025-11/