Description
Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. 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 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 140.10 |
| Mozilla | Thunderbird | — | 140.10 |
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 | 140.10.0esr-1 | — |
| Debian 14 | thunderbird | 1:140.10.0esr-1 | — |
| Debian 13 | firefox-esr | 140.10.0esr-1~deb13u1 | — |
| Debian 13 | thunderbird | 1:140.10.0esr-1~deb13u1 | — |
| Debian 12 | firefox-esr | 140.10.0esr-1~deb12u1 | — |
| Debian 12 | thunderbird | 1:140.10.0esr-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 | 140.10.0-1.el10_1 | RHSA-2026:19131, RHSA-2026:19041, RHSA-2026:12285 |
| RHEL 9 | firefox +2 | 140.10.0-1.el9_7 | RHSA-2026:19348, RHSA-2026:19201, RHSA-2026:15892 |
| RHEL 8 | firefox +1 | 140.10.0-1.el8_10 | RHSA-2026:13537, RHSA-2026:10766 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | firefox +1 | 140.10.0-1.el10_0 | RHSA-2026:19463, RHSA-2026:17690 |
| RHEL 9.6 EUS | firefox +2 | 140.10.0-1.el9_6 | RHSA-2026:19462, RHSA-2026:17688 |
| RHEL 9.4 EUS | firefox +2 | 140.10.0-1.el9_4 | RHSA-2026:19469, RHSA-2026:19464 |
| RHEL 9.2 E4S | firefox +2 | 140.10.0-1.el9_2 | RHSA-2026:19461, RHSA-2026:17689 |
| RHEL 9.0 E4S | firefox +1 | 140.10.0-1.el9_0 | RHSA-2026:19468, RHSA-2026:17687 |
| RHEL 8.8 TUS | firefox +1 | 140.10.0-1.el8_8 | RHSA-2026:19467, RHSA-2026:17477 |
| RHEL 8.8 E4S | firefox +1 | 140.10.0-1.el8_8 | RHSA-2026:19467, RHSA-2026:17477 |
| RHEL 8.6 TUS | firefox +1 | 140.10.0-1.el8_6 | RHSA-2026:19542, RHSA-2026:19466 |
| RHEL 8.6 E4S | firefox +1 | 140.10.0-1.el8_6 | RHSA-2026:19542, RHSA-2026:19466 |
| RHEL 8.6 AUS | firefox +1 | 140.10.0-1.el8_6 | RHSA-2026:19542, RHSA-2026:19466 |
| RHEL 8.4 EUS Long Life | firefox +1 | 140.10.0-1.el8_4 | RHSA-2026:19655, RHSA-2026:19465 |
| RHEL 8.4 AUS | firefox +1 | 140.10.0-1.el8_4 | RHSA-2026:19655, RHSA-2026:19465 |
| RHEL 7 ELS | firefox | 140.10.0-2.el7_9 | RHSA-2026:19704 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | firefox | 140.10.0-1.el10_1 | ALSA-2026:10767 |
| AlmaLinux 10 | thunderbird | 140.10.0-1.el10_1.alma.1 | ALSA-2026:12285 |
| AlmaLinux 9 | firefox +2 | 140.10.0-1.el9_7.alma.1 | ALSA-2026:19348, ALSA-2026:15892, ALSA-2026:10757 |
| AlmaLinux 8 | firefox +1 | 140.10.0-1.el8_10.alma.1 | ALSA-2026:13537, ALSA-2026:10766 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | firefox +1 | 140.10.0-1.el10_1 | RLSA-2026:12285, RLSA-2026:10767 |
| Rocky Linux 9 | firefox +1 | 140.10.0-1.el9_7 | RLSA-2026:19348, RLSA-2026:19201, RLSA-2026:15892 |
| Rocky Linux 8 | firefox +1 | 140.10.0-1.el8_10 | RLSA-2026:13537, RLSA-2026:10766 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 150.0-1.1 | openSUSE-SU-2026:10626-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 140.9.1-1.1 | openSUSE-SU-2026:10610-1 |
| openSUSE Tumbleweed | firefox-esr | 153.0-1.1 | openSUSE-SU-2026:11373-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.10.1-1.amzn2023.0.1 | ALAS2023-2026-1652 |
| Amazon Linux 2 | thunderbird | 140.10.0-1.amzn2.0.1 | ALAS2-2026-3290 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox +1 | 140.10.0-1.0.1.el10_1 | ELSA-2026-19131, ELSA-2026-19041, ELSA-2026-12285 |
| Oracle Linux 9 | firefox +2 | 140.10.0-1.0.1.el9_7 | ELSA-2026-19348, ELSA-2026-19201, ELSA-2026-15892 |
| Oracle Linux 8 | firefox +1 | 140.10.0-1.0.1.el8_10 | ELSA-2026-13537, ELSA-2026-10766 |
| Oracle Linux 7 | firefox | 140.10.0-1.0.1.el7_9 | ELSA-2026-19704 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 140.10-r0 | — |
Advisories 50
- WID-SEC-2026-1228 Mozilla Thunderbird, Firefox ESR und Firefox: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- ALSA-2026:19348 Important: thunderbird security update AlmaLinux Security Advisories · Nov 6, 2026
- ALSA-2026:10767 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:12285 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:10757 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:15892 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:10766 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:13537 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-2455 Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 27, 2026
- RHSA-2026:19348 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 29, 2026
- openSUSE-SU-2026:11373-1 firefox-esr-153.0-1.1 on GA media SUSE / openSUSE Security Updates · Jul 26, 2026
- ELSA-2026-19131 Important: thunderbird security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 20, 2026
- WID-SEC-2026-1730 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Jul 16, 2026
- RHSA-2026:19655 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19704 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19542 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19469 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19467 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19468 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19466 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19465 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19463 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19464 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19461 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19462 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19201 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19131 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:19041 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:17690 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:17688 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:17689 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:17687 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:17477 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:15892 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:13537 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:12285 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:10766 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:10767 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- RHSA-2026:10757 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jul 15, 2026
- ELSA-2026-19041 Important: firefox security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 8, 2026
- ELSA-2026-19348 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 26, 2026
- ELSA-2026-19704 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jun 15, 2026
- ELSA-2026-19201 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 12, 2026
- RLSA-2026:19348 Important: thunderbird security update Rocky Linux Security Advisories · May 28, 2026
- RLSA-2026:19201 Important: firefox security update Rocky Linux Security Advisories · May 20, 2026
- ALAS2-2026-3290 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · May 13, 2026
- ALAS2023-2026-1652 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 13, 2026
- RLSA-2026:15892 Important: thunderbird security update Rocky Linux Security Advisories · May 13, 2026
- ELSA-2026-15892 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · May 11, 2026
- RLSA-2026:12285 Important: thunderbird security update Rocky Linux Security Advisories · May 7, 2026
References
- Memory safety bugs fixed in Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150
- https://www.mozilla.org/security/advisories/mfsa2026-30/
- https://www.mozilla.org/security/advisories/mfsa2026-32/
- https://www.mozilla.org/security/advisories/mfsa2026-33/
- https://www.mozilla.org/security/advisories/mfsa2026-34/