CVE-2026-4689
Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component
02 Description
Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 0.69% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 52.2% of scored records. A rank, not a probability.
- NVD base score
- 10.0 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-07-15.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-03-24 12:30Z7 MO AGO
- Last updated
- 2026-07-15 00:49Z3 MO AGO
- Reserved
- 2026-03-23
- Assigning CNA
- mozilla
- Record state
- PUBLISHED
- Severity
- Critical (CVSS 10.0)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weaknesses
- Data version
- 5.2
- Document digest
- 117747248bc78188e9ffabf110fc5c2bd9a9229b3a750b1164e4445bd58f5bb2
05 Affected products
06 References
- bugzilla.mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=2016374
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-20/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-21/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-22/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-23/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-24/
- access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-4689
- bugzilla.redhat.comRHBZ#2450718https://bugzilla.redhat.com/show_bug.cgi?id=2450718
- security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4689.json
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8427
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7843
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8315
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:5931
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:6342
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:5932
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:6917
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7840
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8285
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7858
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8850
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7842
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8289
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7838
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8288
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7839
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8286
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7841
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8287
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7845
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8290
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7837
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8284
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:5930
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:6188
07 Fixed in
AlmaLinux 8
- firefox Fixed in 140.9.0-1.el8_10.alma.1
- thunderbird Fixed in 140.9.0-1.el8_10.alma.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 9
- firefox Fixed in 140.9.0-1.el9_7.alma.1
- firefox-x11 Fixed in 140.9.0-1.el9_7.alma.1
- thunderbird Fixed in 140.9.0-1.el9_7.alma.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 10
- firefox Fixed in 140.9.0-1.el10_1
- thunderbird Fixed in 140.9.0-1.el10_1.alma.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- firefox Fixed in 140.9.0-1.el8_10.alma.1
- thunderbird Fixed in 140.9.0-1.el8_10.alma.1
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 9
- firefox Fixed in 140.9.0-1.el9_7.alma.1
- firefox-x11 Fixed in 140.9.0-1.el9_7.alma.1
- thunderbird Fixed in 140.9.0-1.el9_7.alma.1
Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 10
- firefox Fixed in 140.9.0-1.el10_1
- thunderbird Fixed in 140.9.0-1.el10_1.alma.1
Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- firefox-esr Fixed in 140.9.0esr-1~deb12u1
- thunderbird Fixed in 1:140.9.0esr-1~deb12u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- firefox-esr Fixed in 140.9.0esr-1~deb13u1
- thunderbird Fixed in 1:140.9.0esr-1~deb13u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- firefox-esr Fixed in 140.9.0esr-1
- thunderbird Fixed in 1:140.9.0esr-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- mozjs38 No fix yet
- mozjs52 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- mozjs52 No fix yet
- mozjs68 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- mozjs102 No fix yet
- mozjs78 No fix yet
- mozjs91 No fix yet
- thunderbird No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- mozjs102 No fix yet
- mozjs115 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.