Description
Internally found bugs present in Firefox ESR 153.0 and Firefox 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | — | 153.1 |
| Mozilla | Thunderbird | — | 153.1 |
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.
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 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLES 15 SP7 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP7 | MozillaThunderbird | 153.2.0-150400.13.3.1 | SUSE-SU-2026:4268-1 |
| SLES 15 SP7 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP7 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP6 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLES 15 SP6 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP6 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP6 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP5 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLES 15 SP5 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP5 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP5 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP4 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLES 15 SP4 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP4 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLES 15 SP4 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLES 12 SP5 | MozillaFirefox | 140.14.0-112.327.1 | SUSE-SU-2026:4140-1, SUSE-SU-2026:3683-1 |
| SLES 12 SP5 | MozillaFirefox-branding-SLE | 153-41.3.8 | SUSE-SU-2026:4140-1 |
| SLES 12 SP5 | mozilla-nspr | 4.39-19.39.1 | SUSE-SU-2026:4140-1 |
| SLES 12 SP5 | mozilla-nss | 3.125-58.147.1 | SUSE-SU-2026:4140-1 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | MozillaFirefox | 153.1.0-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES for SAP 16.0 | MozillaFirefox-branding-SLE | 153-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES for SAP 16.0 | mozilla-nspr | 4.39-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES for SAP 16.0 | mozilla-nss | 3.125-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES for SAP 16.0 | rust-cbindgen | 0.29.4+git0-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES for SAP 15 SP6 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLES for SAP 15 SP6 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP6 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP6 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLES for SAP 15 SP5 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP5 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP5 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLES for SAP 15 SP4 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP4 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLES for SAP 15 SP4 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLES 16.0 | MozillaFirefox | 153.1.0-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES 16.0 | MozillaFirefox-branding-SLE | 153-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES 16.0 | mozilla-nspr | 4.39-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES 16.0 | mozilla-nss | 3.125-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLES 16.0 | rust-cbindgen | 0.29.4+git0-160000.1.1 | SUSE-SU-2026:23590-1 |
| SLE Micro 6.2 | mozilla-nspr | 4.39-160000.1.1 | SUSE-SU-2026:23411-1 |
| SLE Micro 6.2 | mozilla-nss | 3.125-160000.1.1 | SUSE-SU-2026:23411-1 |
| SLE Micro 5.5 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLE Micro 5.5 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLE Micro 5.4 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLE Micro 5.4 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLE Micro 5.3 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLE Micro 5.3 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLE HPC 15 SP5 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLE HPC 15 SP5 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLE HPC 15 SP5 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 140.14.0-150200.152.251.1 | SUSE-SU-2026:4156-1, SUSE-SU-2026:3658-1 |
| SLE HPC 15 SP4 | MozillaFirefox-branding-SLE | 153-150400.14.3.1 | SUSE-SU-2026:4156-1 |
| SLE HPC 15 SP4 | mozilla-nspr | 4.39-150400.12.3.1 | SUSE-SU-2026:4156-1 |
| SLE HPC 15 SP4 | mozilla-nss | 3.125-150400.3.74.1 | SUSE-SU-2026:4156-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 154.0-1.1 | openSUSE-SU-2026:11580-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 153.4.0-1.1 | openSUSE-SU-2026:12098-1 |
| openSUSE Tumbleweed | firefox-esr | 153.1.0-1.1 | openSUSE-SU-2026:11546-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 153.1.0-160000.1.2 | openSUSE-SU-2026:21713-1 |
| openSUSE Leap 16.0 | mozilla-nspr | 4.39-160000.1.1 | openSUSE-SU-2026:21713-1 |
| openSUSE Leap 16.0 | mozilla-nss | 3.125-160000.1.1 | openSUSE-SU-2026:21713-1 |
| openSUSE Leap 16.0 | rust-cbindgen | 0.29.4+git0-160000.1.1 | openSUSE-SU-2026:21713-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.14.0-1.amzn2023.0.1 | ALAS2023-2026-2105 |
| Amazon Linux 2 | thunderbird | 140.14.0-1.amzn2.0.1 | ALAS2-2026-3880 |
Advisories 14
- WID-SEC-2026-2911 Mozilla Firefox, Firefox ESR und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 8, 2026
- openSUSE-SU-2026:12098-1 MozillaThunderbird-153.4.0-1.1 on GA media SUSE / openSUSE Security Updates · Oct 11, 2026
- SUSE-SU-2026:23590-1 Security update for MozillaFirefox, mozilla-nss, mozilla-nspr, rust-cbindgen SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:4140-1 Security update for MozillaFirefox, mozilla-nspr, mozilla-nss, rust-cbindgen SUSE / openSUSE Security Updates · Sep 28, 2026
- SUSE-SU-2026:4268-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Sep 19, 2026
- SUSE-SU-2026:4156-1 Security update for MozillaFirefox, MozillaFirefox-branding-SLE, mozilla-nspr, mozilla-nss, rust-cbindgen SUSE / openSUSE Security Updates · Sep 15, 2026
- SUSE-SU-2026:23411-1 Security update for MozillaFirefox, mozilla-nss, mozilla-nspr, rust-cbindgen SUSE / openSUSE Security Updates · Sep 10, 2026
- openSUSE-SU-2026:21713-1 Security update for MozillaFirefox, mozilla-nss, mozilla-nspr, rust-cbindgen SUSE / openSUSE Security Updates · Sep 2, 2026
- ALAS2-2026-3880 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Aug 31, 2026
- ALAS2023-2026-2105 Important: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 31, 2026
- SUSE-SU-2026:3683-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Aug 26, 2026
- openSUSE-SU-2026:11580-1 MozillaFirefox-154.0-1.1 on GA media SUSE / openSUSE Security Updates · Aug 24, 2026
- openSUSE-SU-2026:11546-1 firefox-esr-153.1.0-1.1 on GA media SUSE / openSUSE Security Updates · Aug 21, 2026
- SUSE-SU-2026:3658-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Aug 21, 2026
References
- Moderate Severity internally found bugs fixed in Firefox ESR 153.1 and Firefox 154
- High Severity internally found bugs fixed in Firefox ESR 153.1 and Firefox 154
- Low Severity internally found bugs fixed in Firefox ESR 153.1 and Firefox 154
- https://www.mozilla.org/security/advisories/mfsa2026-74/
- https://www.mozilla.org/security/advisories/mfsa2026-77/
- https://www.mozilla.org/security/advisories/mfsa2026-78/
- https://www.mozilla.org/security/advisories/mfsa2026-80/