Description
Memory safety bugs present in Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. 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 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 115.33 |
| Mozilla | Thunderbird | — | 140.8 |
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 | 140.8.0esr-1 | — |
| Debian 14 | thunderbird | 1:140.8.0esr-1 | — |
| Debian 13 | firefox-esr | 140.8.0esr-1~deb13u1 | DSA-6148-1 |
| Debian 13 | thunderbird | 1:140.8.0esr-1~deb13u1 | DSA-6152-1 |
| Debian 12 | firefox-esr | 140.8.0esr-1~deb12u1 | DSA-6148-1 |
| Debian 12 | thunderbird | 1:140.8.0esr-1~deb12u1 | DSA-6152-1 |
| Debian 11 | firefox-esr | 140.8.0esr-1~deb11u1 | DLA-4496-1 |
| Debian 11 | thunderbird | 1:140.8.0esr-1~deb11u1 | DLA-4495-1 |
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 | 140.8.0-2.el10_1 | RHSA-2026:3517, RHSA-2026:3361 |
| RHEL 9 | firefox +1 | 140.8.0-2.el9_7 | RHSA-2026:3339 |
| RHEL 9 | thunderbird | 140.8.0-1.el9_7 | RHSA-2026:3516 |
| RHEL 8 | firefox | 140.8.0-2.el8_10 | RHSA-2026:3338 |
| RHEL 8 | thunderbird | 140.8.0-1.el8_10 | RHSA-2026:3515 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | firefox +1 | 140.8.0-2.el10_0 | RHSA-2026:4260, RHSA-2026:3976 |
| RHEL 9.6 EUS | firefox +1 | 140.8.0-2.el9_6 | RHSA-2026:3497 |
| RHEL 9.6 EUS | thunderbird | 140.8.0-1.el9_6 | RHSA-2026:3982 |
| RHEL 9.4 EUS | firefox +1 | 140.8.0-2.el9_4 | RHSA-2026:3496 |
| RHEL 9.4 EUS | thunderbird | 140.8.0-1.el9_4 | RHSA-2026:3981 |
| RHEL 9.2 E4S | firefox +1 | 140.8.0-2.el9_2 | RHSA-2026:4152 |
| RHEL 9.2 E4S | thunderbird | 140.8.0-1.el9_2 | RHSA-2026:3978 |
| RHEL 9.0 E4S | firefox | 140.8.0-2.el9_0 | RHSA-2026:3493 |
| RHEL 9.0 E4S | thunderbird | 140.8.0-1.el9_0 | RHSA-2026:3983 |
| RHEL 8.8 TUS | firefox | 140.8.0-2.el8_8 | RHSA-2026:3494 |
| RHEL 8.8 TUS | thunderbird | 140.8.0-1.el8_8 | RHSA-2026:4022 |
| RHEL 8.8 E4S | firefox | 140.8.0-2.el8_8 | RHSA-2026:3494 |
| RHEL 8.8 E4S | thunderbird | 140.8.0-1.el8_8 | RHSA-2026:4022 |
| RHEL 8.6 TUS | firefox | 140.8.0-2.el8_6 | RHSA-2026:3495 |
| RHEL 8.6 TUS | thunderbird | 140.8.0-1.el8_6 | RHSA-2026:3979 |
| RHEL 8.6 E4S | firefox | 140.8.0-2.el8_6 | RHSA-2026:3495 |
| RHEL 8.6 E4S | thunderbird | 140.8.0-1.el8_6 | RHSA-2026:3979 |
| RHEL 8.6 AUS | firefox | 140.8.0-2.el8_6 | RHSA-2026:3495 |
| RHEL 8.6 AUS | thunderbird | 140.8.0-1.el8_6 | RHSA-2026:3979 |
| RHEL 8.4 EUS Long Life | firefox +1 | 140.8.0-2.el8_4 | RHSA-2026:3980, RHSA-2026:3491 |
| RHEL 8.4 AUS | firefox +1 | 140.8.0-2.el8_4 | RHSA-2026:3980, RHSA-2026:3491 |
| RHEL 8.2 AUS | firefox | 140.8.0-2.el8_2 | RHSA-2026:3492 |
| RHEL 8.2 AUS | thunderbird | 140.8.0-1.el8_2 | RHSA-2026:4432 |
| RHEL 7 ELS | firefox | 140.8.0-2.el7_9 | RHSA-2026:3984 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | firefox | 140.8.0-2.el10_1 | ALSA-2026:3361 |
| AlmaLinux 10 | thunderbird | 140.8.0-2.el10_1.alma.1 | ALSA-2026:3517 |
| AlmaLinux 9 | firefox +1 | 140.8.0-2.el9_7.alma.1 | ALSA-2026:3339 |
| AlmaLinux 9 | thunderbird | 140.8.0-1.el9_7.alma.1 | ALSA-2026:3516 |
| AlmaLinux 8 | firefox | 140.8.0-2.el8_10.alma.1 | ALSA-2026:3338 |
| AlmaLinux 8 | thunderbird | 140.8.0-1.el8_10.alma.1 | ALSA-2026:3515 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | firefox +1 | 140.8.0-2.el10_1 | RLSA-2026:3517, RLSA-2026:3361 |
| Rocky Linux 9 | firefox | 140.8.0-2.el9_7 | RLSA-2026:3339 |
| Rocky Linux 9 | thunderbird | 140.8.0-1.el9_7 | RLSA-2026:3516 |
| Rocky Linux 8 | firefox | 140.8.0-2.el8_10 | RLSA-2026:3338 |
| Rocky Linux 8 | thunderbird | 140.8.0-1.el8_10 | RLSA-2026:3515 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLES 15 SP7 | MozillaThunderbird | 140.8.0-150200.8.260.1 | SUSE-SU-2026:0880-1 |
| SLES 15 SP6 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLES 15 SP5 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLES 15 SP4 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLES 12 SP5 | MozillaFirefox | 140.8.0-112.301.1 | SUSE-SU-2026:0812-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 148.0-1.1 | openSUSE-SU-2026:10257-1 |
| openSUSE Tumbleweed | firefox-esr +1 | 140.8.0-1.1 | openSUSE-SU-2026:10248-1, openSUSE-SU-2026:10242-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 140.8.0-160000.1.1 | openSUSE-SU-2026:20365-1 |
| openSUSE Leap 16.0 | MozillaThunderbird | 140.8.1-bp160.1.1 | openSUSE-SU-2026:20391-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 140.8.0-150200.152.222.1 | SUSE-SU-2026:0871-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 140.8.0-150200.8.260.1 | SUSE-SU-2026:0880-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.8.0-1.amzn2023.0.1 | ALAS2023-2026-1470 |
| Amazon Linux 2 | thunderbird | 140.8.0-1.amzn2.0.1 | ALAS2-2026-3198 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | firefox +1 | 140.8.0-2.0.1.el10_1 | ELSA-2026-3517, ELSA-2026-3361 |
| Oracle Linux 9 | firefox +1 | 140.8.0-2.0.1.el9_7 | ELSA-2026-3339 |
| Oracle Linux 9 | thunderbird | 140.8.0-1.0.1.el9_7 | ELSA-2026-3516 |
| Oracle Linux 8 | firefox | 140.8.0-2.0.1.el8_10 | ELSA-2026-3338 |
| Oracle Linux 8 | thunderbird | 140.8.0-1.0.1.el8_10 | ELSA-2026-3515 |
| Oracle Linux 7 | firefox | 140.8.0-2.0.1.el7_9 | ELSA-2026-3984 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 140.8.0-r0 | — |
Advisories 50
- WID-SEC-2026-0497 Mozilla Firefox, Firefox ESR und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 8, 2026
- ALSA-2026:3361 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:3517 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:3516 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:3339 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:3515 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:3338 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:4432 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:4260 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:4152 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:4022 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3984 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3983 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3982 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3981 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3980 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3978 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3979 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3976 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3517 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3516 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3515 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3497 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3495 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3496 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3493 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3494 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3491 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3492 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3361 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3339 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2026:3338 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- WID-SEC-2026-1730 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Jul 16, 2026
- ELSA-2026-3984 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jun 10, 2026
- ALAS2023-2026-1470 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Mar 27, 2026
- openSUSE-SU-2026:20391-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 26, 2026
- openSUSE-SU-2026:20365-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10257-1 MozillaFirefox-148.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10242-1 firefox-esr-140.8.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2-2026-3198 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Mar 19, 2026
- SUSE-SU-2026:0880-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Mar 13, 2026
- SUSE-SU-2026:0871-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 13, 2026
- DSA-6148-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2026:3515 Important: thunderbird security update Rocky Linux Security Advisories · Mar 9, 2026
- RLSA-2026:3517 Important: thunderbird security update Rocky Linux Security Advisories · Mar 9, 2026
- RLSA-2026:3516 Important: thunderbird security update Rocky Linux Security Advisories · Mar 9, 2026
- SUSE-SU-2026:0812-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Mar 5, 2026
- DLA-4496-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 2, 2026
- ELSA-2026-3516 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Mar 2, 2026
- ELSA-2026-3515 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 2, 2026
References
- Memory safety bugs fixed in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148
- https://www.mozilla.org/security/advisories/mfsa2026-13/
- https://www.mozilla.org/security/advisories/mfsa2026-14/
- https://www.mozilla.org/security/advisories/mfsa2026-15/
- https://www.mozilla.org/security/advisories/mfsa2026-16/
- https://www.mozilla.org/security/advisories/mfsa2026-17/