Description
Using techniques that built on the slipstream research, a malicious webpage could have scanned both an internal network's hosts as well as services running on the user's local machine utilizing WebRTC connections. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox ESR | unspecified – < 78.9 | 78.9 |
| Mozilla | Firefox | unspecified – < 87 | 87 |
| Mozilla | Thunderbird | unspecified – < 78.9 | 78.9 |
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 | 78.9.0esr-1 | — |
| Debian 14 | thunderbird | 1:78.9.0-1 | — |
| Debian 13 | firefox-esr | 78.9.0esr-1 | — |
| Debian 13 | thunderbird | 1:78.9.0-1 | — |
| Debian 12 | firefox-esr | 78.9.0esr-1 | — |
| Debian 12 | thunderbird | 1:78.9.0-1 | — |
| Debian 10 | firefox-esr | 78.9.0esr-1~deb10u1 | DSA-4874-1 |
| Debian 10 | thunderbird | 1:78.9.0-1~deb10u1 | DSA-4876-1 |
| Debian 9 | firefox-esr | 78.9.0esr-1~deb9u1 | DLA-2607-1 |
| Debian 9 | thunderbird | 1:78.9.0-1~deb9u1 | DLA-2609-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | mozjs78 | No fix yet | — |
| Ubuntu 20.04 LTS | firefox | 87.0+build3-0ubuntu0.20.04.2 | USN-4893-1 |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 20.04 LTS | thunderbird | 1:78.11.0+build1-0ubuntu0.20.04.2 | USN-4995-1 |
| Ubuntu 18.04 LTS | firefox | 87.0+build3-0ubuntu0.18.04.2 | USN-4893-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | thunderbird | 1:78.11.0+build1-0ubuntu0.18.04.2 | USN-4995-2 |
| Ubuntu 16.04 LTS | firefox | 87.0+build3-0ubuntu0.16.04.2 | USN-4893-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | firefox | 78.9.0-1.el8_3 | RHSA-2021:0990 |
| RHEL 8 | thunderbird | 78.9.0-3.el8_3 | RHSA-2021:0993 |
| RHEL 7 | firefox | 78.9.0-1.el7_9 | RHSA-2021:0992 |
| RHEL 7 | thunderbird | 78.9.0-3.el7_9 | RHSA-2021:0996 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | firefox | 78.9.0-1.el8_2 | RHSA-2021:0989 |
| RHEL 8.2 EUS | thunderbird | 78.9.0-3.el8_2 | RHSA-2021:0994 |
| RHEL 8.1 EUS | firefox | 78.9.0-1.el8_1 | RHSA-2021:0991 |
| RHEL 8.1 EUS | thunderbird | 78.9.0-3.el8_1 | RHSA-2021:0995 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | MozillaFirefox | 78.9.0-8.35.1 | SUSE-SU-2021:0966-1 |
| SLES 15 SP2 | MozillaThunderbird | 78.9.1-8.20.1 | SUSE-SU-2021:1167-1 |
| SLES 15 SP2 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SLES 15 SP1 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SLES 15 SP1 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SLES 15 SP1 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SLES 15 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SLES 15 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SLES 15 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SLES 12 SP5 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SLES 12 SP4 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
Show 22 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SLES 12 SP2 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SLES 11 SP4 | MozillaFirefox | 78.9.0-78.123.1 | SUSE-SU-2021:14684-1 |
| SLES for SAP 15 SP1 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SLES for SAP 15 SP1 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SLES for SAP 15 SP1 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SLES for SAP 15 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SLES for SAP 15 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SLES for SAP 15 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SLE Micro 5.0 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SLE HPC 15 SP1 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SLE HPC 15 SP1 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SLE HPC 15 SP1 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SLE HPC 15 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SLE HPC 15 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SLE HPC 15 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SUSE Manager Server 4.0 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Server 4.0 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Server 4.0 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Retail Branch Server 4.0 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Retail Branch Server 4.0 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Retail Branch Server 4.0 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Proxy 4.0 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Proxy 4.0 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SUSE Manager Proxy 4.0 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.9.0-112.54.1 | SUSE-SU-2021:0999-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox | 78.9.0-3.136.1 | SUSE-SU-2021:1007-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox-branding-SLE | 78-4.16.1 | SUSE-SU-2021:1007-1 |
| SUSE Enterprise Storage 6 | mozilla-nspr | 4.25.1-3.17.1 | SUSE-SU-2021:1007-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 78.9.0-lp152.2.52.1 | openSUSE-SU-2021:0487-1 |
| openSUSE Leap 15.2 | MozillaThunderbird | 78.9.1-lp152.2.38.1 | openSUSE-SU-2021:0580-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 87.0-r0 | — |
| Alpine v3.23 | firefox +1 | 87.0-r0 | — |
| Alpine v3.23 | firefox-esr +1 | 78.9.0-r0 | — |
| Alpine v3.22 | firefox +1 | 87.0-r0 | — |
| Alpine v3.22 | firefox-esr +1 | 78.9.0-r0 | — |
| Alpine v3.21 | firefox +1 | 87.0-r0 | — |
| Alpine v3.21 | firefox-esr +1 | 78.9.0-r0 | — |
| Alpine v3.20 | firefox | 87.0-r0 | — |
| Alpine v3.20 | firefox-esr +1 | 78.9.0-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 87.0-r0 | — |
| Alpine v3.19 | firefox-esr +1 | 78.9.0-r0 | — |
| Alpine v3.18 | firefox | 87.0-r0 | — |
| Alpine v3.18 | firefox-esr +1 | 78.9.0-r0 | — |
| Alpine v3.17 | firefox | 87.0-r0 | — |
| Alpine v3.17 | firefox-esr +1 | 78.9.0-r0 | — |
| Alpine v3.16 | firefox | 87.0-r0 | — |
| Alpine v3.16 | firefox-esr +1 | 78.9.0-r0 | — |
| Alpine v3.15 | firefox | 87.0-r0 | — |
| Alpine v3.15 | firefox-esr | 78.9.0-r0 | — |
| Alpine v3.14 | firefox | 87.0-r0 | — |
| Alpine v3.14 | firefox-esr | 78.9.0-r0 | — |
| Alpine v3.13 | firefox | 87.0-r0 | — |
| Alpine v3.13 | firefox-esr | 78.9.0-r0 | — |
| Alpine v3.12 | firefox-esr | 78.9.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 78.9.0-3.amzn2 | ALAS2-2021-1632 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | firefox | 78.9.0-1.0.1.el8_3 | ELSA-2021-0990 |
| Oracle Linux 8 | thunderbird | 78.9.0-3.0.1.el8_3 | ELSA-2021-0993 |
| Oracle Linux 7 | firefox | 78.9.0-1.0.1.el7_9 | ELSA-2021-0992 |
| Oracle Linux 7 | thunderbird | 78.9.0-3.0.1.el7_9 | ELSA-2021-0996 |
Advisories 30
- RHSA-2021:0992 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2021:0996 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4995-2 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-4995-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-4893-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4876-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4874-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2607-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2609-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2021:0487-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1167-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0999-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0580-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14684-1 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
- SUSE-SU-2021:0966-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2021:0995 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:0994 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:0993 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:0991 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:0989 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:0990 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- SUSE-SU-2021:1007-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2021-1632 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 21, 2021
- ELSA-2021-0990 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 26, 2021
- ELSA-2021-0993 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 26, 2021
- ELSA-2021-0996 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 26, 2021
- ELSA-2021-0992 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 25, 2021