Description
`EncryptingOutputStream` was susceptible to exposing uninitialized data. This issue could only be abused in order to write data to a local disk which may have implications for private browsing mode. This vulnerability affects Firefox ESR < 115.6 and Firefox < 121.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox ESR | unspecified – < 115.6 | 115.6 |
| Mozilla | Firefox | unspecified – < 121 | 121 |
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 | 115.6.0esr-1 | — |
| Debian 13 | firefox-esr | 115.6.0esr-1 | — |
| Debian 12 | firefox-esr | 115.6.0esr-1~deb12u1 | DSA-5581-1 |
| Debian 11 | firefox-esr | 115.6.0esr-1~deb11u1 | DSA-5581-1 |
| Debian 10 | firefox-esr | 115.6.0esr-1~deb10u1 | DLA-3697-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | mozjs102 | No fix yet | — |
| Ubuntu 22.04 LTS | mozjs78 +2 | No fix yet | — |
| Ubuntu 20.04 LTS | firefox | 121.0+build1-0ubuntu0.20.04.1 | USN-6562-1 |
| 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 9 | firefox +1 | 115.6.0-1.el9_3 | RHSA-2024:0025 |
| RHEL 8 | firefox | 115.6.0-1.el8_9 | RHSA-2024:0012 |
| RHEL 7 | firefox | 115.6.0-1.el7_9 | RHSA-2024:0026 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.2 EUS | firefox +1 | 115.6.0-1.el9_2 | RHSA-2024:0019 |
| RHEL 9.0 EUS | firefox | 115.6.0-1.el9_0 | RHSA-2024:0022 |
| RHEL 8.8 EUS | firefox | 115.6.0-1.el8_8 | RHSA-2024:0011 |
| RHEL 8.6 EUS | firefox | 115.6.0-1.el8_6 | RHSA-2024:0024 |
| RHEL 8.4 TUS | firefox | 115.6.0-1.el8_4 | RHSA-2024:0021 |
| RHEL 8.4 E4S | firefox | 115.6.0-1.el8_4 | RHSA-2024:0021 |
| RHEL 8.4 AUS | firefox | 115.6.0-1.el8_4 | RHSA-2024:0021 |
| RHEL 8.2 TUS | firefox | 115.6.0-1.el8_2 | RHSA-2024:0023 |
| RHEL 8.2 E4S | firefox | 115.6.0-1.el8_2 | RHSA-2024:0023 |
| RHEL 8.2 AUS | firefox | 115.6.0-1.el8_2 | RHSA-2024:0023 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | firefox +1 | 115.6.0-1.el9_3.alma | ALSA-2024:0025 |
| AlmaLinux 8 | firefox | 115.6.0-1.el8_9.alma | ALSA-2024:0012 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox | 115.6.0-1.el8_9 | RLSA-2024:0012 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLES 15 SP4 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLES 15 SP3 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLES 15 SP2 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLES 15 SP1 | MozillaFirefox | 115.6.0-150000.150.119.1 | SUSE-SU-2023:4929-1 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | MozillaFirefox | 115.6.0-112.194.1 | SUSE-SU-2023:4912-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLES for SAP 15 SP2 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLES for SAP 15 SP1 | MozillaFirefox | 115.6.0-150000.150.119.1 | SUSE-SU-2023:4929-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 115.6.0-112.194.1 | SUSE-SU-2023:4912-1 |
| SLE Real Time 15 SP4 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLE HPC 15 SP2 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| SLE HPC 15 SP1 | MozillaFirefox | 115.6.0-150000.150.119.1 | SUSE-SU-2023:4929-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 121.0-1.1 | openSUSE-SU-2024:13531-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.5 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
| openSUSE Leap 15.4 | MozillaFirefox | 115.6.0-150200.152.120.1 | SUSE-SU-2023:4928-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.23 | firefox-esr | 115.6.0-r0 | — |
| Alpine v3.22 | firefox-esr | 115.6.0-r0 | — |
| Alpine v3.21 | firefox-esr | 115.6.0-r0 | — |
| Alpine v3.20 | firefox-esr | 115.6.0-r0 | — |
| Alpine v3.19 | firefox-esr | 115.6.0-r0 | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.18 | firefox-esr | 115.6.0-r0 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | firefox +1 | 115.6.0-1.0.1.el9_3 | ELSA-2024-0025 |
| Oracle Linux 8 | firefox | 115.6.0-1.0.1.el8_9 | ELSA-2024-0012 |
| Oracle Linux 7 | firefox | 115.6.0-1.0.1.el7_9 | ELSA-2024-0026 |
Advisories 25
- ALSA-2024:0025 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2024:0012 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2024:0026 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-6562-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- RHSA-2024:0022 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:0023 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:0012 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:0019 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:0021 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:0024 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:0025 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2024:0011 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Mar 18, 2026
- DSA-5581-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3697-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2024:0012 Important: firefox security update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2023:4912-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:13531-1 MozillaFirefox-121.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4928-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4929-1 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-2023-3185 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 2, 2025
- WID-SEC-2024-1248 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 21, 2024
- ELSA-2024-0012 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jan 3, 2024
- ELSA-2024-0025 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jan 3, 2024
- ELSA-2024-0026 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jan 2, 2024
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1864123
- https://www.mozilla.org/security/advisories/mfsa2023-54/
- https://www.mozilla.org/security/advisories/mfsa2023-56/
- https://www.debian.org/security/2023/dsa-5581
- https://lists.debian.org/debian-lts-announce/2023/12/msg00020.html
- https://security.gentoo.org/glsa/202401-10