Sandbox escape due to incorrect boundary conditions in the Graphics component

published 2026-09-15 54 d ago modified 2026-10-05 34 d ago also EUVD-2026-78498

cvss: 9.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits: 0; none known

Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Thunderbird 140.17, Firefox 156, Firefox ESR 153.3, Thunderbird 156, Thunderbird 153.3, Firefox ESR 115.42, and Firefox ESR 140.17.

Patch / fix

fixed in 2 distros 5

mozilla firefox 115.42.0, 140.17.0, 153.3.0, 156.0.0
mozilla thunderbird 140.17.0, 153.3.0, 156.0

debian suse opensuse almalinux rocky linux

thunderbird Debian 12 1:140.17.0esr-1~deb12u1
thunderbird Debian 13 1:140.17.0esr-1~deb13u1
thunderbird Debian 14 1:153.3.0esr-1

debian advisories DEBIAN-CVE-2026-92035

MozillaThunderbird SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 153.4.0-150400.13.6.1
MozillaFirefox SLES for SAP applications 16.0, SLES 16.0 153.3.0-160000.1.1
MozillaFirefox SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 153.3.0-150400.157.8.1
MozillaFirefox SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 153.3.0-118.8.1

suse advisories SUSE-SU-2026:4627-1 SUSE-SU-2026:23918-1 SUSE-SU-2026:4264-1 SUSE-SU-2026:4247-1

MozillaThunderbird openSUSE Tumbleweed 153.4.0-1.1
MozillaFirefox openSUSE Leap 16.0 153.3.0-160000.1.1
MozillaFirefox openSUSE Tumbleweed 156.0-1.1
firefox-esr openSUSE Tumbleweed 153.3.0-1.1

opensuse advisories openSUSE-SU-2026:12098-1 openSUSE-SU-2026:21951-1 openSUSE-SU-2026:11826-1 openSUSE-SU-2026:11796-1

thunderbird AlmaLinux 8 140.17.0-1.el8_10.alma.1
firefox AlmaLinux 9 140.17.0-1.el9_8.alma.1
firefox-x11 AlmaLinux 9 140.17.0-1.el9_8.alma.1
firefox AlmaLinux 10 140.17.0-1.el10_2
firefox AlmaLinux 8 140.17.0-1.el8_10.alma.1

almalinux advisories ALSA-2026:90913 ALSA-2026:76761 ALSA-2026:76764 ALSA-2026:76850

thunderbird Rocky Linux 8 140.17.0-1.el8_10
firefox Rocky Linux 10 140.17.0-1.el10_2
firefox Rocky Linux 9 140.17.0-1.el9_8
firefox Rocky Linux 8 140.17.0-1.el8_10

rocky linux advisories RLSA-2026:90913 RLSA-2026:76764 RLSA-2026:76761 RLSA-2026:76850

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-92035 updated 2026-11-05 cvss 7.5

firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics component

Red Hat Enterprise Linux AppStream (v. 8) firefox 140.17.0-1.el8_10, thunderbird 140.17.0-1.el8_10
fixed: vendor fix RHSA-2026:76850
Red Hat Enterprise Linux AppStream (v. 9) firefox 140.17.0-1.el9_8, firefox-x11 140.17.0-1.el9_8
fixed: vendor fix RHSA-2026:76761
Red Hat Enterprise Linux AppStream (v. 10) firefox 140.17.0-1.el10_2
fixed: vendor fix RHSA-2026:76764
Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox 140.17.0-1.el8_4
fixed: vendor fix RHSA-2026:92011
Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox 140.17.0-1.el8_6, thunderbird 140.17.0-1.el8_6
fixed: vendor fix RHSA-2026:92228
Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox 140.17.0-1.el8_8, thunderbird 140.17.0-1.el8_8
fixed: vendor fix RHSA-2026:92327
Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox 140.17.0-1.el9_2, firefox-x11 140.17.0-1.el9_2
fixed: vendor fix RHSA-2026:92226
Red Hat Enterprise Linux AppStream E4S (v.9.4) firefox 140.17.0-1.el9_4, firefox-x11 140.17.0-1.el9_4
fixed: vendor fix RHSA-2026:92012

show 7 more

Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox 140.17.0-1.el10_0
fixed: vendor fix RHSA-2026:92227
Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox 140.17.0-1.el9_6, firefox-x11 140.17.0-1.el9_6
fixed: vendor fix RHSA-2026:92335
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox 140.17.0-1.el8_4
fixed: vendor fix RHSA-2026:92011
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) firefox 140.17.0-1.el8_6, thunderbird 140.17.0-1.el8_6
fixed: vendor fix RHSA-2026:92228
Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox 140.17.0-1.el8_8, thunderbird 140.17.0-1.el8_8
fixed: vendor fix RHSA-2026:92327
Red Hat Enterprise Linux Server (v. 7 ELS) firefox 140.17.0-1.el7_9
fixed: vendor fix RHSA-2026:92363
Red Hat Enterprise Linux 6 firefox, thunderbird Red Hat Enterprise Linux 7 thunderbird Red Hat Enterprise Linux 9 thunderbird Red Hat Enterprise Linux 10 thunderbird, rhel10/firefox-flatpak, rhel10/thunderbird-flatpak
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 48 d ago (2026-09-21)

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.6	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CNA	3.1	9.6	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Affected products

Mozilla Firefox
Mozilla Thunderbird

Classification

Weakness

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

mozilla.org /security/advisories/mfsa2026-102/
vendor-advisory
mozilla.org /security/advisories/mfsa2026-90/
vendor-advisory
mozilla.org /security/advisories/mfsa2026-93/
vendor-advisory
mozilla.org /security/advisories/mfsa2026-94/
vendor-advisory
mozilla.org /security/advisories/mfsa2026-96/
vendor-advisory
mozilla.org /security/advisories/mfsa2026-98/
vendor-advisory
mozilla.org /security/advisories/mfsa2026-99/
vendor-advisory
bugzilla.mozilla.org /show_bug.cgi?id=2061245
permissions-required

Sources

CVE List CVE-2026-92035
NVD CVE-2026-92035

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary