Description
Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. 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 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 140.7 |
| Mozilla | Thunderbird | — | 140.7 |
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 | 140.7.0esr-1 | — |
| Debian 14 | thunderbird | 1:140.7.0esr-1 | — |
| Debian 13 | firefox-esr | 140.7.0esr-1~deb13u1 | DSA-6101-1 |
| Debian 13 | thunderbird | 1:140.7.0esr-1~deb13u1 | DSA-6103-1 |
| Debian 12 | firefox-esr | 140.7.0esr-1~deb12u1 | DSA-6101-1 |
| Debian 12 | thunderbird | 1:140.7.0esr-1~deb12u1 | DSA-6103-1 |
| Debian 11 | firefox-esr | 140.7.0esr-1~deb11u1 | DLA-4439-1 |
| Debian 11 | thunderbird | 1:140.7.0esr-1~deb11u1 | DLA-4442-1 |
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 | 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 | 140.7.0-1.el10_1 | RHSA-2026:2286, RHSA-2026:2271 |
| RHEL 9 | firefox +2 | 140.7.0-1.el9_7 | RHSA-2026:0924, RHSA-2026:0694 |
| RHEL 8 | firefox +1 | 140.7.0-1.el8_10 | RHSA-2026:2220, RHSA-2026:0667 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | firefox +1 | 140.7.0-1.el10_0 | RHSA-2026:2286, RHSA-2026:2271 |
| RHEL 9.6 EUS | firefox +1 | 140.7.0-1.el9_6 | RHSA-2026:2043 |
| RHEL 9.6 EUS | thunderbird | 140.7.0-2.el9_6 | RHSA-2026:1320 |
| RHEL 9.4 EUS | firefox +2 | 140.7.0-1.el9_4 | RHSA-2026:2041, RHSA-2026:1414 |
| RHEL 9.2 E4S | firefox +2 | 140.7.0-1.el9_2 | RHSA-2026:2044, RHSA-2026:1415 |
| RHEL 9.0 E4S | firefox +1 | 140.7.0-1.el9_0 | RHSA-2026:2047, RHSA-2026:1413 |
| RHEL 8.8 TUS | firefox +1 | 140.7.0-1.el8_8 | RHSA-2026:2069, RHSA-2026:1462 |
| RHEL 8.8 E4S | firefox +1 | 140.7.0-1.el8_8 | RHSA-2026:2069, RHSA-2026:1462 |
| RHEL 8.6 TUS | firefox +1 | 140.7.0-1.el8_6 | RHSA-2026:2070, RHSA-2026:1487 |
| RHEL 8.6 E4S | firefox +1 | 140.7.0-1.el8_6 | RHSA-2026:2070, RHSA-2026:1487 |
| RHEL 8.6 AUS | firefox +1 | 140.7.0-1.el8_6 | RHSA-2026:2070, RHSA-2026:1487 |
| RHEL 8.4 EUS Long Life | firefox +1 | 140.7.0-1.el8_4 | RHSA-2026:2073, RHSA-2026:1461 |
| RHEL 8.4 AUS | firefox +1 | 140.7.0-1.el8_4 | RHSA-2026:2073, RHSA-2026:1461 |
| RHEL 8.2 AUS | firefox +1 | 140.7.0-1.el8_2 | RHSA-2026:2074, RHSA-2026:1471 |
| RHEL 7 ELS | firefox | 140.7.0-1.el7_9 | RHSA-2026:2231 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | firefox | 140.7.0-1.el10_1 | ALSA-2026:2271 |
| AlmaLinux 10 | thunderbird | 140.7.0-1.el10_1.alma.1 | ALSA-2026:2286 |
| AlmaLinux 9 | firefox +2 | 140.7.0-1.el9_7.alma.1 | ALSA-2026:0924, ALSA-2026:0694 |
| AlmaLinux 8 | firefox +1 | 140.7.0-1.el8_10.alma.1 | ALSA-2026:2220, ALSA-2026:0667 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 9 | firefox +1 | 140.7.0-1.el9_7 | RLSA-2026:0924, RLSA-2026:0694 |
| Rocky Linux 8 | firefox +1 | 140.7.0-1.el8_10 | RLSA-2026:2220, RLSA-2026:0667 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLES 15 SP7 | MozillaThunderbird | 140.7.0-150200.8.251.1 | SUSE-SU-2026:0153-1 |
| SLES 15 SP6 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLES 15 SP5 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLES 15 SP4 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLES 12 SP5 | MozillaFirefox | 140.7.0-112.295.1 | SUSE-SU-2026:0122-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | MozillaFirefox | 140.7.0-160000.1.1 | SUSE-SU-2026:20086-1 |
| SLES for SAP 15 SP6 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLES 16.0 | MozillaFirefox | 140.7.0-160000.1.1 | SUSE-SU-2026:20086-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 147.0-1.1 | openSUSE-SU-2026:10046-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 140.7.0-1.1 | openSUSE-SU-2026:10058-1, openSUSE-SU-2026:10037-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 140.7.0-160000.1.1 | openSUSE-SU-2026:20041-1 |
| openSUSE Leap 16.0 | MozillaThunderbird | 140.8.1-bp160.1.1 | openSUSE-SU-2026:20391-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 140.7.0-150200.152.216.1 | SUSE-SU-2026:0260-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 140.7.0-150200.8.251.1 | SUSE-SU-2026:0153-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.7.0-1.amzn2023.0.1 | ALAS2023-2026-1429 |
| Amazon Linux 2 | thunderbird | 140.7.1-1.amzn2.0.1 | ALAS2-2026-3167 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox +1 | 140.7.0-1.0.1.el10_1 | ELSA-2026-2286, ELSA-2026-2271 |
| Oracle Linux 9 | firefox +2 | 140.7.0-1.0.1.el9_7 | ELSA-2026-0924, ELSA-2026-0694 |
| Oracle Linux 8 | firefox +1 | 140.7.0-1.0.1.el8_10 | ELSA-2026-2220, ELSA-2026-0667 |
| Oracle Linux 7 | firefox | 140.7.0-1.0.1.el7_9 | ELSA-2026-2231 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 140.7-r0 | — |
Advisories 50
- WID-SEC-2026-0090 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 5, 2026
- ALSA-2026:2286 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:2271 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:0924 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:0694 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:0667 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:2220 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:2286 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2271 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2231 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2220 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2074 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2073 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2070 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2069 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2047 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2044 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2043 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:2041 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1487 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1471 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1462 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1461 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1414 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1415 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1413 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:1320 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0924 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0694 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:0667 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- WID-SEC-2026-1730 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Jul 16, 2026
- openSUSE-SU-2026:20391-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 26, 2026
- openSUSE-SU-2026:20041-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10058-1 MozillaThunderbird-140.7.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10046-1 MozillaFirefox-147.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10037-1 firefox-esr-140.7.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20086-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0260-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0153-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0122-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2-2026-3167 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Feb 18, 2026
- ALAS2023-2026-1429 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 18, 2026
- ELSA-2026-2231 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 18, 2026
- RLSA-2026:2220 Important: thunderbird security update Rocky Linux Security Advisories · Feb 9, 2026
- ELSA-2026-2286 Important: thunderbird security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Feb 9, 2026
- ELSA-2026-2271 Important: firefox security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Feb 9, 2026
- ELSA-2026-2220 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 9, 2026
- RLSA-2026:0924 Important: thunderbird security update Rocky Linux Security Advisories · Jan 22, 2026
- ELSA-2026-0924 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jan 21, 2026
- DLA-4442-1 thunderbird - security update Debian Security (DSA / DLA) · Jan 19, 2026
References
- Memory safety bugs fixed in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147
- https://www.mozilla.org/security/advisories/mfsa2026-01/
- https://www.mozilla.org/security/advisories/mfsa2026-03/
- https://www.mozilla.org/security/advisories/mfsa2026-04/
- https://www.mozilla.org/security/advisories/mfsa2026-05/