Description
Memory safety bugs present in Firefox 136, Thunderbird 136, Firefox ESR 128.8, and Thunderbird 128.8. 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 137, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 128.9 |
| Mozilla | Thunderbird | — | 128.9 |
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 | 128.9.0esr-1 | — |
| Debian 14 | thunderbird | 1:128.9.0esr-1 | — |
| Debian 13 | firefox-esr | 128.9.0esr-1 | — |
| Debian 13 | thunderbird | 1:128.9.0esr-1 | — |
| Debian 12 | firefox-esr | 128.9.0esr-1~deb12u1 | DSA-5889-1 |
| Debian 12 | thunderbird | 1:128.9.0esr-1~deb12u1 | DSA-5891-1 |
| Debian 11 | firefox-esr | 128.9.0esr-1~deb11u1 | DLA-4109-1 |
| Debian 11 | thunderbird | 1:128.9.0esr-1~deb11u1 | DLA-4110-1 |
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 | 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 | 128.9.0-3.el10_0 | RHSA-2025:7491 |
| RHEL 10 | thunderbird | 128.9.0-2.el10_0 | RHSA-2025:7493 |
| RHEL 9 | firefox +2 | 128.9.0-2.el9_5 | RHSA-2025:4169, RHSA-2025:3556 |
| RHEL 8 | firefox +1 | 128.9.0-2.el8_10 | RHSA-2025:4170, RHSA-2025:3582 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.4 EUS | firefox +2 | 128.9.0-2.el9_4 | RHSA-2025:4026, RHSA-2025:3590 |
| RHEL 9.2 EUS | firefox +2 | 128.9.0-2.el9_2 | RHSA-2025:4027, RHSA-2025:3589 |
| RHEL 9.0 E4S | firefox +1 | 128.9.0-2.el9_0 | RHSA-2025:4028, RHSA-2025:3587 |
| RHEL 8.8 EUS | firefox +1 | 128.9.0-2.el8_8 | RHSA-2025:4029, RHSA-2025:3620 |
| RHEL 8.6 TUS | firefox +1 | 128.9.0-2.el8_6 | RHSA-2025:4030, RHSA-2025:3621 |
| RHEL 8.6 E4S | firefox +1 | 128.9.0-2.el8_6 | RHSA-2025:4030, RHSA-2025:3621 |
| RHEL 8.6 AUS | firefox +1 | 128.9.0-2.el8_6 | RHSA-2025:4030, RHSA-2025:3621 |
| RHEL 8.4 TUS | firefox +1 | 128.9.0-2.el8_4 | RHSA-2025:4031, RHSA-2025:3581 |
| RHEL 8.4 E4S | firefox +1 | 128.9.0-2.el8_4 | RHSA-2025:4031, RHSA-2025:3581 |
| RHEL 8.4 AUS | firefox +1 | 128.9.0-2.el8_4 | RHSA-2025:4031, RHSA-2025:3581 |
| RHEL 8.2 AUS | firefox +1 | 128.9.0-2.el8_2 | RHSA-2025:4032, RHSA-2025:3623 |
| RHEL 7 ELS | firefox | 128.9.0-2.el7_9 | RHSA-2025:3628 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | firefox +1 | 128.9.0-2.el9_5 | ALSA-2025:3556 |
| AlmaLinux 9 | thunderbird | 128.9.0-2.el9_5.alma.1 | ALSA-2025:4169 |
| AlmaLinux 8 | firefox | 128.9.0-2.el8_10 | ALSA-2025:3582 |
| AlmaLinux 8 | thunderbird | 128.9.0-2.el8_10.alma.1 | ALSA-2025:4170 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox +1 | 128.9.0-2.el8_10 | RLSA-2025:4170, RLSA-2025:3582 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLES 15 SP6 | MozillaThunderbird | 128.9.0-150200.8.206.1 | SUSE-SU-2025:1157-1 |
| SLES 15 SP5 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLES 15 SP4 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLES 15 SP3 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLES 12 SP5 | MozillaFirefox | 128.9.0-112.252.1 | SUSE-SU-2025:1103-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP5 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 137.0-1.1 | openSUSE-SU-2025:14971-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 128.9.0-1.1 | openSUSE-SU-2025:14966-1, openSUSE-SU-2025:14961-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 128.9.0-150200.152.176.1 | SUSE-SU-2025:1138-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 128.9.0-150200.8.206.1 | SUSE-SU-2025:1157-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 128.9.0-1.amzn2023.0.1 | ALAS2023-2025-943 |
| Amazon Linux 2 | thunderbird | 128.9.1-1.amzn2.0.1 | ALAS2-2025-2840 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox +1 | 128.11.0-1.0.1.el10_0 | ELSA-2025-7493, ELSA-2025-7491 |
| Oracle Linux 9 | firefox +2 | 128.9.0-2.0.1.el9_5 | ELSA-2025-4169, ELSA-2025-3556 |
| Oracle Linux 8 | firefox +1 | 128.9.0-2.0.1.el8_10 | ELSA-2025-4170, ELSA-2025-3582 |
| Oracle Linux 7 | firefox | 128.9.0-2.0.1.el7_9 | ELSA-2025-3628 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 128.9-r0 | — |
Advisories 48
- ALSA-2025:3556 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:4169 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:3582 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:4170 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2025:4030 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2025:3556 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2025:7491 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:7493 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4169 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4170 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4032 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4031 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4028 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4029 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4027 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:4026 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3628 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3623 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3621 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3620 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3590 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3589 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3587 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3581 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2025:3582 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- USN-7663-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5891-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-5889-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4109-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4110-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2025:1157-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14971-1 MozillaFirefox-137.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14966-1 MozillaThunderbird-128.9.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14961-1 firefox-esr-128.9.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:1138-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-0675 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 2, 2026
- RLSA-2025:4170 Important: thunderbird security update Rocky Linux Security Advisories · Jul 29, 2025
- RLSA-2025:3582 Important: firefox security update Rocky Linux Security Advisories · Jul 29, 2025
- ELSA-2025-7493 Important: thunderbird security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jun 30, 2025
- ELSA-2025-7491 Important: firefox security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jun 30, 2025
- SUSE-SU-2025:1103-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2025-2840 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 30, 2025
- ALAS2023-2025-943 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Apr 29, 2025
- ELSA-2025-4169 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Apr 24, 2025
- ELSA-2025-4170 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Apr 24, 2025
- ELSA-2025-3628 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 22, 2025
- ELSA-2025-3556 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Apr 3, 2025
- ELSA-2025-3582 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Apr 3, 2025
References
- Memory safety bugs fixed in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9
- https://www.mozilla.org/security/advisories/mfsa2025-20/
- https://www.mozilla.org/security/advisories/mfsa2025-22/
- https://www.mozilla.org/security/advisories/mfsa2025-23/
- https://www.mozilla.org/security/advisories/mfsa2025-24/