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OpenAdvisories
Critical · 9.6 Public exploit CVE-2026-4692 EUVD-2026-14807GHSA-cm3f-xp4p-xgj7

Sandbox escape in the Responsive Design Mode component

Published Mar 24, 2026 · Updated Jul 15, 2026 · Assigned by mozilla

Description

Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Affected products

VendorProductAffectedFixed
Mozilla Firefox — 115.34
Mozilla Thunderbird — 140.9

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.

ReleasePackageFixed inAdvisory
Debian 14 firefox-esr 140.9.0esr-1 —
Debian 14 thunderbird 1:140.9.0esr-1 —
Debian 13 firefox-esr 140.9.0esr-1~deb13u1 DSA-6178-1
Debian 13 thunderbird 1:140.9.0esr-1~deb13u1 DSA-6179-1
Debian 12 firefox-esr 140.9.0esr-1~deb12u1 DSA-6178-1
Debian 12 thunderbird 1:140.9.0esr-1~deb12u1 DSA-6179-1
Debian 11 firefox-esr 140.9.0esr-1~deb11u1 DLA-4510-1
Debian 11 thunderbird 1:140.9.0esr-1~deb11u1 DLA-4511-1
ReleasePackageFixed inAdvisory
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 —
ReleasePackageFixed inAdvisory
RHEL 10 firefox +1 140.9.0-1.el10_1 RHSA-2026:6342, RHSA-2026:5931
RHEL 9 firefox +2 140.9.0-1.el9_7 RHSA-2026:6188, RHSA-2026:5930
RHEL 8 firefox +1 140.9.0-1.el8_10 RHSA-2026:6917, RHSA-2026:5932
Show 14 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
RHEL 10.0 EUS firefox +1 140.9.0-1.el10_0 RHSA-2026:8315, RHSA-2026:7843
RHEL 9.6 EUS firefox +2 140.9.0-1.el9_6 RHSA-2026:8284, RHSA-2026:7837
RHEL 9.4 EUS firefox +2 140.9.0-1.el9_4 RHSA-2026:8290, RHSA-2026:7845
RHEL 9.2 E4S firefox +2 140.9.0-1.el9_2 RHSA-2026:8287, RHSA-2026:7841
RHEL 9.0 E4S firefox +1 140.9.0-1.el9_0 RHSA-2026:8286, RHSA-2026:7839
RHEL 8.8 TUS firefox +1 140.9.0-1.el8_8 RHSA-2026:8288, RHSA-2026:7838
RHEL 8.8 E4S firefox +1 140.9.0-1.el8_8 RHSA-2026:8288, RHSA-2026:7838
RHEL 8.6 TUS firefox +1 140.9.0-1.el8_6 RHSA-2026:8289, RHSA-2026:7842
RHEL 8.6 E4S firefox +1 140.9.0-1.el8_6 RHSA-2026:8289, RHSA-2026:7842
RHEL 8.6 AUS firefox +1 140.9.0-1.el8_6 RHSA-2026:8289, RHSA-2026:7842
RHEL 8.4 EUS Long Life firefox +1 140.9.0-1.el8_4 RHSA-2026:8850, RHSA-2026:7858
RHEL 8.4 AUS firefox +1 140.9.0-1.el8_4 RHSA-2026:8850, RHSA-2026:7858
RHEL 8.2 AUS firefox +1 140.9.0-1.el8_2 RHSA-2026:8285, RHSA-2026:7840
RHEL 7 ELS firefox 140.9.0-1.el7_9 RHSA-2026:8427

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 10 firefox 140.9.0-1.el10_1 ALSA-2026:5931
AlmaLinux 10 thunderbird 140.9.0-1.el10_1.alma.1 ALSA-2026:6342
AlmaLinux 9 firefox +2 140.9.0-1.el9_7.alma.1 ALSA-2026:6188, ALSA-2026:5930
AlmaLinux 8 firefox +1 140.9.0-1.el8_10.alma.1 ALSA-2026:6917, ALSA-2026:5932

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 10 firefox +1 140.9.0-1.el10_1 RLSA-2026:6342, RLSA-2026:5931
Rocky Linux 9 firefox +1 140.9.0-1.el9_7 RLSA-2026:6188, RLSA-2026:5930
Rocky Linux 8 firefox +1 140.9.0-1.el8_10 RLSA-2026:6917, RLSA-2026:5932
ReleasePackageFixed inAdvisory
SLES 15 SP7 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLES 15 SP6 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLES 15 SP5 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLES 15 SP4 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLES 12 SP5 MozillaFirefox 140.9.0-112.304.2 SUSE-SU-2026:1127-1
Show 7 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 MozillaFirefox 140.9.0-160000.1.1 SUSE-SU-2026:20978-1
SLES for SAP 15 SP6 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLES for SAP 15 SP5 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLES for SAP 15 SP4 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLES 16.0 MozillaFirefox 140.9.0-160000.1.1 SUSE-SU-2026:20978-1
SLE HPC 15 SP5 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
SLE HPC 15 SP4 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed MozillaFirefox 149.0-1.1 openSUSE-SU-2026:10458-1
openSUSE Tumbleweed firefox-esr +1 140.9.0-1.1 openSUSE-SU-2026:10447-1, openSUSE-SU-2026:10413-1
openSUSE Leap 16.0 MozillaFirefox 140.9.0-160000.1.1 openSUSE-SU-2026:20439-1
openSUSE Leap 15.6 MozillaFirefox 140.9.0-150200.152.225.1 SUSE-SU-2026:1126-1
openSUSE Leap 15.6 MozillaThunderbird 140.9.0-150200.8.263.1 SUSE-SU-2026:1163-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 firefox 140.9.0-1.amzn2023.0.2 ALAS2023-2026-1554
Amazon Linux 2 thunderbird 140.9.0-1.amzn2.0.2 ALAS2-2026-3241

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 10 firefox +1 140.9.0-1.0.1.el10_1 ELSA-2026-6342, ELSA-2026-5931
Oracle Linux 9 firefox +2 140.9.0-1.0.1.el9_7 ELSA-2026-6188, ELSA-2026-5930
Oracle Linux 8 firefox +1 140.9.0-1.0.1.el8_10 ELSA-2026-6917, ELSA-2026-5932
Oracle Linux 7 firefox 140.9.0-1.0.1.el7_9 ELSA-2026-8427

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling firefox 149.0-r0 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

  • Firefox BrowsingContext field-sync authz bypass (N-day, bug 2017643): forged PContent::CommitBrowsingContextTransaction sets InRDMPane=true from a compromised content process - parent applies it. Pre…

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 50

References