Description
Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, and Thunderbird 128.7. 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 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 115.21 |
| Mozilla | Thunderbird | — | 128.8 |
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 | 128.8.0esr-1 | — |
| Debian 14 | thunderbird | 1:128.8.0esr-1 | — |
| Debian 13 | firefox-esr | 128.8.0esr-1 | — |
| Debian 13 | thunderbird | 1:128.8.0esr-1 | — |
| Debian 12 | firefox-esr | 128.8.0esr-1~deb12u1 | DSA-5874-1 |
| Debian 12 | thunderbird | 1:128.8.0esr-1~deb12u1 | DSA-5876-1 |
| Debian 11 | firefox-esr | 128.8.0esr-1~deb11u1 | DLA-4078-1 |
| Debian 11 | thunderbird | 1:128.8.0esr-1~deb11u1 | DLA-4081-1 |
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 | 136.0+build3-0ubuntu0.20.04.1 | USN-7334-1 |
| 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 +1 | 128.8.0-1.el9_5 | RHSA-2025:2359 |
| RHEL 9 | thunderbird | 128.8.0-2.el9_5 | RHSA-2025:2899 |
| RHEL 8 | firefox | 128.8.0-1.el8_10 | RHSA-2025:2452 |
| RHEL 8 | thunderbird | 128.8.0-2.el8_10 | RHSA-2025:2900 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.4 EUS | firefox +1 | 128.8.0-1.el9_4 | RHSA-2025:2479 |
| RHEL 9.4 EUS | thunderbird | 128.8.0-2.el9_4 | RHSA-2025:2957 |
| RHEL 9.2 EUS | firefox +1 | 128.8.0-1.el9_2 | RHSA-2025:2480 |
| RHEL 9.2 EUS | thunderbird | 128.8.0-2.el9_2 | RHSA-2025:2959 |
| RHEL 9.0 E4S | firefox | 128.8.0-1.el9_0 | RHSA-2025:2481 |
| RHEL 9.0 E4S | thunderbird | 128.8.0-2.el9_0 | RHSA-2025:3013 |
| RHEL 8.8 EUS | firefox | 128.8.0-1.el8_8 | RHSA-2025:2486 |
| RHEL 8.8 EUS | thunderbird | 128.8.0-2.el8_8 | RHSA-2025:2958 |
| RHEL 8.6 TUS | firefox | 128.8.0-1.el8_6 | RHSA-2025:2485 |
| RHEL 8.6 TUS | thunderbird | 128.8.0-2.el8_6 | RHSA-2025:3036 |
| RHEL 8.6 E4S | firefox | 128.8.0-1.el8_6 | RHSA-2025:2485 |
| RHEL 8.6 E4S | thunderbird | 128.8.0-2.el8_6 | RHSA-2025:3036 |
| RHEL 8.6 AUS | firefox | 128.8.0-1.el8_6 | RHSA-2025:2485 |
| RHEL 8.6 AUS | thunderbird | 128.8.0-2.el8_6 | RHSA-2025:3036 |
| RHEL 8.4 TUS | firefox | 128.8.0-1.el8_4 | RHSA-2025:2484 |
| RHEL 8.4 TUS | thunderbird | 128.8.0-2.el8_4 | RHSA-2025:3009 |
| RHEL 8.4 E4S | firefox | 128.8.0-1.el8_4 | RHSA-2025:2484 |
| RHEL 8.4 E4S | thunderbird | 128.8.0-2.el8_4 | RHSA-2025:3009 |
| RHEL 8.4 AUS | firefox | 128.8.0-1.el8_4 | RHSA-2025:2484 |
| RHEL 8.4 AUS | thunderbird | 128.8.0-2.el8_4 | RHSA-2025:3009 |
| RHEL 8.2 AUS | firefox | 128.8.0-1.el8_2 | RHSA-2025:2708 |
| RHEL 8.2 AUS | thunderbird | 128.8.0-2.el8_2 | RHSA-2025:2960 |
| RHEL 7 ELS | firefox | 128.8.0-1.el7_9 | RHSA-2025:2699 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | firefox +1 | 128.8.0-1.el9_5 | ALSA-2025:2359 |
| AlmaLinux 9 | thunderbird | 128.8.0-2.el9_5.alma.1 | ALSA-2025:2899 |
| AlmaLinux 8 | firefox | 128.8.0-1.el8_10 | ALSA-2025:2452 |
| AlmaLinux 8 | thunderbird | 128.8.0-2.el8_10.alma.1 | ALSA-2025:2900 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox | 128.8.0-1.el8_10 | RLSA-2025:2452 |
| Rocky Linux 8 | thunderbird | 128.8.0-2.el8_10 | RLSA-2025:2900 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLES 15 SP6 | MozillaThunderbird | 128.8.0-150200.8.203.1 | SUSE-SU-2025:0849-1 |
| SLES 15 SP5 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLES 15 SP4 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLES 15 SP3 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLES 12 SP5 | MozillaFirefox | 128.8.0-112.249.3 | SUSE-SU-2025:0783-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP5 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 136.0-1.1 | openSUSE-SU-2025:14861-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 128.8.0-1.1 | openSUSE-SU-2025:14853-1, openSUSE-SU-2025:14852-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 128.8.0-150200.152.173.1 | SUSE-SU-2025:0788-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 128.8.0-150200.8.203.1 | SUSE-SU-2025:0849-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 128.8.1-1.amzn2.0.1 | ALAS2-2025-2807 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | firefox +1 | 128.8.0-1.0.1.el9_5 | ELSA-2025-2359 |
| Oracle Linux 9 | thunderbird | 128.8.0-2.0.1.el9_5 | ELSA-2025-2899 |
| Oracle Linux 8 | firefox | 128.8.0-1.0.1.el8_10 | ELSA-2025-2452 |
| Oracle Linux 8 | thunderbird | 128.8.0-2.0.1.el8_10 | ELSA-2025-2900 |
| Oracle Linux 7 | firefox | 128.8.0-1.0.1.el7_9 | ELSA-2025-2699 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 136-r0 | — |
Advisories 44
- ALSA-2025:2900 Important: thunderbird security update AlmaLinux Security Advisories · Nov 6, 2026
- ALSA-2025:2359 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:2899 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:2452 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2025:2959 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:3009 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2899 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:3036 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2900 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:3013 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2957 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2958 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2960 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- USN-7663-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-7334-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- RHSA-2025:2708 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2699 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2485 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2486 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2481 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2484 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2480 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2452 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2479 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- RHSA-2025:2359 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 27, 2026
- DSA-5874-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-5876-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4081-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4078-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2025:0849-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14861-1 MozillaFirefox-136.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:0788-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14852-1 firefox-esr-128.8.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:0783-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-0482 Mozilla Firefox, Mozilla Firefox ESR und Mozilla Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 2, 2026
- RLSA-2025:2452 Important: firefox security update Rocky Linux Security Advisories · Jul 29, 2025
- RLSA-2025:2900 Important: thunderbird security update Rocky Linux Security Advisories · May 7, 2025
- openSUSE-SU-2025:14853-1 MozillaThunderbird-128.8.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ALAS2-2025-2807 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 1, 2025
- ELSA-2025-2899 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Mar 17, 2025
- ELSA-2025-2900 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 17, 2025
- ELSA-2025-2699 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 17, 2025
- ELSA-2025-2452 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 6, 2025
- ELSA-2025-2359 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Mar 5, 2025
References
- Memory safety bugs fixed in Firefox 136, Thunderbird 136, Firefox ESR 115.21, Firefox ESR 128.8, and Thunderbird 128.8
- https://www.mozilla.org/security/advisories/mfsa2025-14/
- https://www.mozilla.org/security/advisories/mfsa2025-15/
- https://www.mozilla.org/security/advisories/mfsa2025-16/
- https://www.mozilla.org/security/advisories/mfsa2025-17/
- https://www.mozilla.org/security/advisories/mfsa2025-18/