Description
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. 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 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 140.12 |
| Mozilla | Thunderbird | — | 140.12 |
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 | 140.12.0esr-1 | — |
| Debian 14 | thunderbird | 1:140.12.0esr-1 | — |
| Debian 13 | firefox-esr | 140.12.0esr-1~deb13u1 | — |
| Debian 13 | thunderbird | 1:140.12.0esr-1~deb13u1 | — |
| Debian 12 | firefox-esr | 140.12.0esr-1~deb12u1 | — |
| Debian 12 | thunderbird | 1:140.12.0esr-1~deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | mozjs102 +1 | No fix yet | — |
| Ubuntu 22.04 LTS | mozjs78 +3 | No fix yet | — |
| 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 +1 | 140.12.0-1.el10_2 | RHSA-2026:30846, RHSA-2026:27733 |
| RHEL 9 | firefox +2 | 140.12.0-1.el9_8 | RHSA-2026:29940, RHSA-2026:27734 |
| RHEL 8 | firefox +1 | 140.12.0-1.el8_10 | RHSA-2026:33445, RHSA-2026:27717 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | firefox +1 | 140.12.0-1.el10_0 | RHSA-2026:38751, RHSA-2026:36100 |
| RHEL 9.6 EUS | firefox +2 | 140.12.0-1.el9_6 | RHSA-2026:38750, RHSA-2026:37391 |
| RHEL 9.4 E4S | firefox +2 | 140.12.0-1.el9_4 | RHSA-2026:39011, RHSA-2026:38753 |
| RHEL 9.2 E4S | firefox +2 | 140.12.0-1.el9_2 | RHSA-2026:39706, RHSA-2026:36101 |
| RHEL 8.8 TUS | firefox +1 | 140.12.0-1.el8_8 | RHSA-2026:39142, RHSA-2026:36103 |
| RHEL 8.8 E4S | firefox +1 | 140.12.0-1.el8_8 | RHSA-2026:39142, RHSA-2026:36103 |
| RHEL 8.6 EUS Long Life | firefox +1 | 140.12.0-1.el8_6 | RHSA-2026:39141, RHSA-2026:37210 |
| RHEL 8.6 AUS | firefox +1 | 140.12.0-1.el8_6 | RHSA-2026:39141, RHSA-2026:37210 |
| RHEL 8.4 EUS Long Life | firefox +1 | 140.12.0-1.el8_4 | RHSA-2026:39428, RHSA-2026:36102 |
| RHEL 8.4 AUS | firefox +1 | 140.12.0-1.el8_4 | RHSA-2026:39428, RHSA-2026:36102 |
| RHEL 7 ELS | firefox | 140.12.0-1.el7_9 | RHSA-2026:38506 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | firefox | 140.12.0-1.el10_2 | ALSA-2026:27733 |
| AlmaLinux 10 | thunderbird | 140.12.0-1.el10_2.alma.1 | ALSA-2026:30846 |
| AlmaLinux 9 | firefox +2 | 140.12.0-1.el9_8.alma.1 | ALSA-2026:29940, ALSA-2026:27734 |
| AlmaLinux 8 | firefox +1 | 140.12.0-1.el8_10.alma.1 | ALSA-2026:33445, ALSA-2026:27717 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | firefox +1 | 140.12.0-1.el10_2 | RLSA-2026:30846, RLSA-2026:27733 |
| Rocky Linux 9 | firefox +1 | 140.12.0-1.el9_8 | RLSA-2026:29940, RLSA-2026:27734 |
| Rocky Linux 8 | firefox +1 | 140.12.0-1.el8_10 | RLSA-2026:33445, RLSA-2026:27717 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLES 15 SP7 | MozillaThunderbird | 140.12.0-150200.8.277.1 | SUSE-SU-2026:2852-1 |
| SLES 15 SP6 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLES 15 SP5 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLES 15 SP4 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLES 12 SP5 | MozillaFirefox | 140.12.0-112.321.1 | SUSE-SU-2026:2583-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | MozillaFirefox | 140.12.0-160000.1.1 | SUSE-SU-2026:23137-1, SUSE-SU-2026:23115-1, SUSE-SU-2026:22351-1 |
| SLES for SAP 15 SP6 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLES 16.0 | MozillaFirefox | 140.12.0-160000.1.1 | SUSE-SU-2026:23137-1, SUSE-SU-2026:23115-1, SUSE-SU-2026:22351-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 140.12.0-150200.152.245.1 | SUSE-SU-2026:2814-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 152.0-1.1 | openSUSE-SU-2026:11052-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 140.12.0-1.1 | openSUSE-SU-2026:11072-1, openSUSE-SU-2026:11055-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 140.12.0-160000.1.1 | openSUSE-SU-2026:21519-1, openSUSE-SU-2026:21043-1 |
| openSUSE Leap 16.0 | MozillaThunderbird | 140.12.0-bp160.1.1 | openSUSE-SU-2026:21168-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.12.0-1.amzn2023.0.1 | ALAS2023-2026-1928 |
| Amazon Linux 2 | thunderbird | 140.12.0-1.amzn2.0.1 | ALAS2-2026-3795 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox +1 | 140.12.0-1.0.1.el10_2 | ELSA-2026-30846, ELSA-2026-27733 |
| Oracle Linux 9 | firefox +2 | 140.12.0-1.0.1.el9_8 | ELSA-2026-29940, ELSA-2026-27734 |
| Oracle Linux 8 | firefox +1 | 140.12.0-1.0.1.el8_10 | ELSA-2026-33445, ELSA-2026-27717 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 140.12-r0 | — |
Advisories 50
- RHSA-2026:27734 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- ALSA-2026:29940 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:27734 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:30846 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:27733 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:27717 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:33445 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-1959 Mozilla Firefox, Firefox ESR und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 16, 2026
- SUSE-SU-2026:23137-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Aug 14, 2026
- SUSE-SU-2026:23115-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Aug 14, 2026
- openSUSE-SU-2026:21519-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Aug 4, 2026
- ELSA-2026-27733 Important: firefox security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 17, 2026
- RHSA-2026:39706 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:39428 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:39142 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:39141 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:39011 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:38753 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:38750 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:38751 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:38506 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:37391 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:37210 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:36103 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:36102 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:36101 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:36100 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:33445 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:30846 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:29940 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:27733 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- RHSA-2026:27717 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 16, 2026
- ELSA-2026-30846 Important: thunderbird security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 16, 2026
- SUSE-SU-2026:2852-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Jul 13, 2026
- SUSE-SU-2026:2814-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Jul 10, 2026
- ALAS2-2026-3795 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 7, 2026
- ALAS2023-2026-1928 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 7, 2026
- RLSA-2026:30846 Important: thunderbird security update Rocky Linux Security Advisories · Jul 5, 2026
- RLSA-2026:33445 Important: thunderbird security update Rocky Linux Security Advisories · Jul 4, 2026
- SUSE-SU-2026:22351-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Jul 2, 2026
- openSUSE-SU-2026:21043-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Jun 30, 2026
- openSUSE-SU-2026:21168-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Jun 30, 2026
- ELSA-2026-33445 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jun 30, 2026
- RLSA-2026:29940 Important: thunderbird security update Rocky Linux Security Advisories · Jun 26, 2026
- ELSA-2026-29940 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 26, 2026
- RLSA-2026:27717 Important: firefox security update Rocky Linux Security Advisories · Jun 25, 2026
- RLSA-2026:27733 Important: firefox security update Rocky Linux Security Advisories · Jun 24, 2026
- RLSA-2026:27734 Important: firefox security update Rocky Linux Security Advisories · Jun 24, 2026
- openSUSE-SU-2026:11072-1 MozillaThunderbird-140.12.0-1.1 on GA media SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:2583-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Jun 24, 2026
References
- Moderate Severity memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
- https://www.mozilla.org/security/advisories/mfsa2026-57/
- https://www.mozilla.org/security/advisories/mfsa2026-58/
- https://www.mozilla.org/security/advisories/mfsa2026-60/
- https://www.mozilla.org/security/advisories/mfsa2026-61/