Description
Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. The most likely outcome is connection failure, but if the connection persists despite the high packet loss it could be possible for a network observer to identify packets as coming from the same source despite a network path change. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 129 | 129 |
| Mozilla | Firefox ESR | unspecified – < 115.14, unspecified – < 128.1 | 115.14 |
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 | 115.14.0esr-1 | — |
| Debian 14 | nss | 2:3.103-1 | — |
| Debian 13 | firefox-esr | 115.14.0esr-1 | — |
| Debian 13 | nss | 2:3.103-1 | — |
| Debian 12 | firefox-esr | 115.14.0esr-1~deb12u1 | DSA-5740-1 |
| Debian 12 | nss | No fix yet | — |
| Debian 11 | firefox-esr | 115.14.0esr-1~deb11u1 | DSA-5740-1 |
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 20.04 LTS | firefox | 129.0.1+build1-0ubuntu0.20.04.1 | USN-6966-1 |
| 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 SP6 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP6 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP5 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP5 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP4 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP4 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP3 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP3 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP2 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES 15 SP2 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | MozillaFirefox | 128.1.0-112.221.1 | SUSE-SU-2024:2876-1 |
| SLES 12 SP5 | MozillaFirefox-branding-SLE | 128-35.15.1 | SUSE-SU-2024:2876-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES for SAP 15 SP4 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES for SAP 15 SP3 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLES for SAP 15 SP2 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLES for SAP 15 SP2 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 128.1.0-112.221.1 | SUSE-SU-2024:2876-1 |
| SLES for SAP 12 SP5 | MozillaFirefox-branding-SLE | 128-35.15.1 | SUSE-SU-2024:2876-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLE HPC 15 SP4 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLE HPC 15 SP3 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SLE HPC 15 SP2 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SLE HPC 15 SP2 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 129.0-1.1 | openSUSE-SU-2024:14260-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| openSUSE Leap 15.6 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
| openSUSE Leap 15.5 | MozillaFirefox | 128.1.0-150200.152.146.1 | SUSE-SU-2024:3003-1 |
| openSUSE Leap 15.5 | MozillaFirefox-branding-SLE | 128-150200.9.16.1 | SUSE-SU-2024:3003-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 129.0.2-r0 | — |
Advisories 8
- USN-6966-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5740-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2024:2876-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14260-1 MozillaFirefox-129.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3003-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-1783 Mozilla Firefox, Firefox ESR und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 17, 2025
- NCSC-2024-0324 Kwetsbaarheden verholpen in Mozilla Firefox en Thunderbird NCSC-NL (Netherlands) · Aug 7, 2024