Description
A web page could trick a user into setting that site as the default handler for a custom URL protocol. This vulnerability was fixed in Firefox 136, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 128.8 |
| 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 8 | firefox | 128.8.0-1.el8_10 | RHSA-2025:2452 |
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 9.2 EUS | firefox +1 | 128.8.0-1.el9_2 | RHSA-2025:2480 |
| RHEL 9.0 E4S | firefox | 128.8.0-1.el9_0 | RHSA-2025:2481 |
| RHEL 8.8 EUS | firefox | 128.8.0-1.el8_8 | RHSA-2025:2486 |
| RHEL 8.6 TUS | firefox | 128.8.0-1.el8_6 | RHSA-2025:2485 |
| RHEL 8.6 E4S | firefox | 128.8.0-1.el8_6 | RHSA-2025:2485 |
| RHEL 8.6 AUS | firefox | 128.8.0-1.el8_6 | RHSA-2025:2485 |
| RHEL 8.4 TUS | firefox | 128.8.0-1.el8_4 | RHSA-2025:2484 |
| RHEL 8.4 E4S | firefox | 128.8.0-1.el8_4 | RHSA-2025:2484 |
| RHEL 8.4 AUS | firefox | 128.8.0-1.el8_4 | RHSA-2025:2484 |
| RHEL 8.2 AUS | firefox | 128.8.0-1.el8_2 | RHSA-2025:2708 |
| 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 8 | firefox | 128.8.0-1.el8_10 | ALSA-2025:2452 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox | 128.8.0-1.el8_10 | RLSA-2025:2452 |
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 Tumbleweed | mozjs128 | 128.8.1-1.1 | openSUSE-SU-2025:14958-1 |
| 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 8 | firefox | 128.8.0-1.0.1.el8_10 | ELSA-2025-2452 |
| 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 31
- ALSA-2025:2359 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:2452 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 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-2025:2486 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-2025:2481 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
- openSUSE-SU-2025:14958-1 libmozjs-128-0-128.8.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 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
- 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-2025-2699 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