Description
Memory safety bugs present in Thunderbird ESR 140.12. 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 ESR 115.38, Firefox ESR 140.13, and Thunderbird 140.13.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 115.38 |
| Mozilla | Thunderbird | — | 140.13 |
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 | 140.13.0esr-1 | — |
| Debian 14 | thunderbird | 1:140.13.0esr-1 | — |
| Debian 13 | firefox-esr | 140.13.0esr-1~deb13u1 | — |
| Debian 13 | thunderbird | 1:140.13.0esr-2~deb13u1 | — |
| Debian 12 | firefox-esr | 140.13.0esr-1~deb12u1 | — |
| Debian 12 | thunderbird | 1:140.13.0esr-2~deb12u1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | firefox +1 | 140.13.0-1.el10_2 | RHSA-2026:49621, RHSA-2026:47101 |
| RHEL 9 | firefox +2 | 140.13.0-1.el9_8 | RHSA-2026:49921, RHSA-2026:47104 |
| RHEL 8 | firefox +1 | 140.13.0-1.el8_10 | RHSA-2026:49922, RHSA-2026:47105 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | firefox +1 | 140.13.0-1.el10_0 | RHSA-2026:54181, RHSA-2026:53445 |
| RHEL 9.6 EUS | firefox +2 | 140.13.0-1.el9_6 | RHSA-2026:54249, RHSA-2026:53446 |
| RHEL 9.4 E4S | firefox +2 | 140.13.0-1.el9_4 | RHSA-2026:54182, RHSA-2026:53444 |
| RHEL 9.2 E4S | firefox +2 | 140.13.0-1.el9_2 | RHSA-2026:54185, RHSA-2026:53475 |
| RHEL 8.8 TUS | firefox +1 | 140.13.0-1.el8_8 | RHSA-2026:54339, RHSA-2026:53454 |
| RHEL 8.8 E4S | firefox +1 | 140.13.0-1.el8_8 | RHSA-2026:54339, RHSA-2026:53454 |
| RHEL 8.6 EUS Long Life | firefox +1 | 140.13.0-1.el8_6 | RHSA-2026:54259, RHSA-2026:53453 |
| RHEL 8.6 AUS | firefox +1 | 140.13.0-1.el8_6 | RHSA-2026:54259, RHSA-2026:53453 |
| RHEL 8.4 EUS Long Life | firefox +1 | 140.13.0-1.el8_4 | RHSA-2026:54180, RHSA-2026:53455 |
| RHEL 8.4 AUS | firefox +1 | 140.13.0-1.el8_4 | RHSA-2026:54180, RHSA-2026:53455 |
| RHEL 7 ELS | firefox | 140.13.0-1.el7_9 | RHSA-2026:54248 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | firefox | 140.13.0-1.el10_2 | ALSA-2026:47101 |
| AlmaLinux 10 | thunderbird | 140.13.0-1.el10_2.alma.1 | ALSA-2026:49621 |
| AlmaLinux 9 | firefox +2 | 140.13.0-1.el9_8.alma.1 | ALSA-2026:49921, ALSA-2026:47104 |
| AlmaLinux 8 | firefox +1 | 140.13.0-1.el8_10.alma.1 | ALSA-2026:49922, ALSA-2026:47105 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | firefox +1 | 140.13.0-1.el10_2 | RLSA-2026:49621, RLSA-2026:47101 |
| Rocky Linux 9 | firefox +1 | 140.13.0-1.el9_8 | RLSA-2026:49921, RLSA-2026:47104 |
| Rocky Linux 8 | firefox +1 | 140.13.0-1.el8_10 | RLSA-2026:49922, RLSA-2026:47105 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLES 15 SP7 | MozillaThunderbird | 140.13.0-150200.8.280.1 | SUSE-SU-2026:3546-1 |
| SLES 15 SP6 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLES 15 SP5 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLES 15 SP4 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLES 12 SP5 | MozillaFirefox | 140.13.0-112.324.2 | SUSE-SU-2026:3200-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | MozillaFirefox | 140.13.0-160000.1.1 | SUSE-SU-2026:23137-1, SUSE-SU-2026:23115-1 |
| SLES for SAP 15 SP6 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLES 16.0 | MozillaFirefox | 140.13.0-160000.1.1 | SUSE-SU-2026:23137-1, SUSE-SU-2026:23115-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 140.13.0-150200.152.248.1 | SUSE-SU-2026:3221-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | firefox-esr +1 | 140.13.0-1.1 | openSUSE-SU-2026:11359-1, openSUSE-SU-2026:11329-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 140.13.0-160000.1.1 | openSUSE-SU-2026:21519-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.13.0-1.amzn2023.0.1 | ALAS2023-2026-2069 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox +1 | 140.13.0-1.0.1.el10_2 | ELSA-2026-49621, ELSA-2026-47101 |
| Oracle Linux 9 | firefox +2 | 140.13.0-1.0.1.el9_8 | ELSA-2026-49921, ELSA-2026-47104 |
| Oracle Linux 8 | firefox +1 | 140.13.0-1.0.1.el8_10 | ELSA-2026-49922, ELSA-2026-47105 |
| Oracle Linux 7 | firefox | 140.13.0-1.0.1.el7_9 | ELSA-2026-54248 |
Advisories 50
- WID-SEC-2026-2458 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 8, 2026
- ALSA-2026:47104 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:49921 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:49621 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:47101 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:49922 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:47105 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:54339 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:54259 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:54248 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:54249 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:54185 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:54181 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:54182 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:54180 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:47105 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:47104 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- ELSA-2026-54248 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Sep 21, 2026
- RHSA-2026:53444 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:53445 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:53446 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:53453 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:53454 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:53455 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:53475 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:47101 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:49921 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:49922 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- RHSA-2026:49621 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Sep 9, 2026
- ALAS2023-2026-2069 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 17, 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
- SUSE-SU-2026:3546-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Aug 11, 2026
- RLSA-2026:49921 Important: thunderbird security update Rocky Linux Security Advisories · Aug 6, 2026
- RLSA-2026:49621 Important: thunderbird security update Rocky Linux Security Advisories · Aug 6, 2026
- RLSA-2026:49922 Important: thunderbird security update Rocky Linux Security Advisories · Aug 6, 2026
- openSUSE-SU-2026:21519-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Aug 4, 2026
- ELSA-2026-49922 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Aug 4, 2026
- ELSA-2026-49921 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Aug 4, 2026
- RLSA-2026:47104 Important: firefox security update Rocky Linux Security Advisories · Aug 3, 2026
- ELSA-2026-49621 Important: thunderbird security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Aug 3, 2026
- RLSA-2026:47101 Important: firefox security update Rocky Linux Security Advisories · Jul 30, 2026
- RLSA-2026:47105 Important: firefox security update Rocky Linux Security Advisories · Jul 29, 2026
- ELSA-2026-47104 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 29, 2026
- ELSA-2026-47105 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jul 28, 2026
- ELSA-2026-47101 Important: firefox security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 28, 2026
- openSUSE-SU-2026:11359-1 MozillaThunderbird-140.13.0-1.1 on GA media SUSE / openSUSE Security Updates · Jul 25, 2026
- SUSE-SU-2026:3221-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Jul 24, 2026
- openSUSE-SU-2026:11329-1 firefox-esr-140.13.0-1.1 on GA media SUSE / openSUSE Security Updates · Jul 23, 2026
- SUSE-SU-2026:3200-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Jul 23, 2026