Description
When segmenting specially crafted text, segmentation would corrupt memory leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 128.6 |
| Mozilla | Thunderbird | — | 128.6 |
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 | 128.6.0esr-1 | — |
| Debian 14 | thunderbird | 1:128.6.0esr-1 | — |
| Debian 13 | firefox-esr | 128.6.0esr-1 | — |
| Debian 13 | thunderbird | 1:128.6.0esr-1 | — |
| Debian 12 | firefox-esr | 128.6.0esr-1~deb12u1 | DSA-5839-1 |
| Debian 12 | thunderbird | 1:128.6.0esr-1~deb12u1 | DSA-5841-1 |
| Debian 11 | firefox-esr | 128.6.0esr-1~deb11u3 | DLA-4011-1 |
| Debian 11 | thunderbird | 1:128.6.0esr-1~deb11u1 | DLA-4012-1 |
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 | firefox | 134.0+build1-0ubuntu0.20.04.1 | USN-7191-1 |
| 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 | 128.6.0-1.el9_5 | RHSA-2025:0080 |
| RHEL 9 | thunderbird | 128.6.0-3.el9_5 | RHSA-2025:0147 |
| RHEL 8 | firefox | 128.6.0-1.el8_10 | RHSA-2025:0144 |
| RHEL 8 | thunderbird | 128.6.0-3.el8_10 | RHSA-2025:0281 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.4 EUS | firefox +1 | 128.6.0-1.el9_4 | RHSA-2025:0135 |
| RHEL 9.4 EUS | thunderbird | 128.6.0-3.el9_4 | RHSA-2025:0166 |
| RHEL 9.2 EUS | firefox +1 | 128.6.0-1.el9_2 | RHSA-2025:0138 |
| RHEL 9.2 EUS | thunderbird | 128.6.0-3.el9_2 | RHSA-2025:0167 |
| RHEL 9.0 E4S | firefox | 128.6.0-1.el9_0 | RHSA-2025:0162 |
| RHEL 9.0 E4S | thunderbird | 128.6.0-3.el9_0 | RHSA-2025:0165 |
| RHEL 8.8 EUS | firefox | 128.6.0-1.el8_8 | RHSA-2025:0137 |
| RHEL 8.8 EUS | thunderbird | 128.6.0-3.el8_8 | RHSA-2025:0284 |
| RHEL 8.6 TUS | firefox | 128.6.0-1.el8_6 | RHSA-2025:0136 |
| RHEL 8.6 TUS | thunderbird | 128.6.0-3.el8_6 | RHSA-2025:0275 |
| RHEL 8.6 E4S | firefox | 128.6.0-1.el8_6 | RHSA-2025:0136 |
| RHEL 8.6 E4S | thunderbird | 128.6.0-3.el8_6 | RHSA-2025:0275 |
| RHEL 8.6 AUS | firefox | 128.6.0-1.el8_6 | RHSA-2025:0136 |
| RHEL 8.6 AUS | thunderbird | 128.6.0-3.el8_6 | RHSA-2025:0275 |
| RHEL 8.4 TUS | firefox | 128.6.0-1.el8_4 | RHSA-2025:0134 |
| RHEL 8.4 TUS | thunderbird | 128.6.0-3.el8_4 | RHSA-2025:0287 |
| RHEL 8.4 E4S | firefox | 128.6.0-1.el8_4 | RHSA-2025:0134 |
| RHEL 8.4 E4S | thunderbird | 128.6.0-3.el8_4 | RHSA-2025:0287 |
| RHEL 8.4 AUS | firefox | 128.6.0-1.el8_4 | RHSA-2025:0134 |
| RHEL 8.4 AUS | thunderbird | 128.6.0-3.el8_4 | RHSA-2025:0287 |
| RHEL 8.2 AUS | firefox | 128.6.0-1.el8_2 | RHSA-2025:0133 |
| RHEL 8.2 AUS | thunderbird | 128.6.0-3.el8_2 | RHSA-2025:0286 |
| RHEL 7 ELS | firefox | 128.6.0-1.el7_9 | RHSA-2025:0132 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | firefox +1 | 128.6.0-1.el9_5 | ALSA-2025:0080 |
| AlmaLinux 8 | firefox | 128.6.0-1.el8_10 | ALSA-2025:0144 |
| AlmaLinux 8 | thunderbird | 128.6.0-3.el8_10.alma.1 | ALSA-2025:0281 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox | 128.6.0-1.el8_10 | RLSA-2025:0144 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLES 15 SP6 | MozillaThunderbird | 128.6.0-150200.8.197.1 | SUSE-SU-2025:0080-1 |
| SLES 15 SP5 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLES 15 SP4 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLES 15 SP3 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLES 12 SP5 | MozillaFirefox | 128.6.0-112.243.1 | SUSE-SU-2025:0056-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP5 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 134.0-1.1 | openSUSE-SU-2025:14630-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 128.6.0-1.1 | openSUSE-SU-2025:14648-1, openSUSE-SU-2025:14619-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 128.6.0-150200.152.167.1 | SUSE-SU-2025:0059-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 128.6.0-150200.8.197.1 | SUSE-SU-2025:0080-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | firefox +1 | 128.6.0-1.0.1.el9_5 | ELSA-2025-0080 |
| Oracle Linux 8 | firefox | 128.6.0-1.0.1.el8_10 | ELSA-2025-0144 |
| Oracle Linux 7 | firefox | 128.6.0-1.0.1.el7_9 | ELSA-2025-0132 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 134.0-r0 | — |
Advisories 39
- ALSA-2025:0281 Important: thunderbird security update AlmaLinux Security Advisories · Nov 6, 2026
- ALSA-2025:0080 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:0144 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- USN-7191-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- RHSA-2025:0286 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0287 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0284 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0275 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0281 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0167 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0165 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0166 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0162 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0144 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0147 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0138 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0137 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0135 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0136 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0134 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0133 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0080 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- RHSA-2025:0132 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Apr 14, 2026
- DSA-5841-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-5839-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4012-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4011-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2025:0144 Important: firefox security update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2025:0056-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14648-1 MozillaThunderbird-128.6.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:0080-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14619-1 firefox-esr-128.6.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:0059-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-0026 Mozilla Firefox, Firefox ESR und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 2, 2026
- openSUSE-SU-2025:14630-1 MozillaFirefox-134.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2025-0132 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jan 16, 2025
- NCSC-2025-0016 Kwetsbaarheden verholpen in Mozilla Firefox en Thunderbird NCSC-NL (Netherlands) · Jan 15, 2025
- ELSA-2025-0080 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jan 10, 2025
- ELSA-2025-0144 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jan 10, 2025