CVE-2026-0877
Mitigation bypass in the DOM: Security component
02 Description
Mitigation bypass in the DOM: Security 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 ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.47% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 40.6% of scored records. A rank, not a probability.
- NVD base score
- 8.1 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
- 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
- 2026-01-13 13:30Z9 MO AGO
- Last updated
- 2026-07-15 11:47Z3 MO AGO
- Reserved
- 2026-01-13
- Assigning CNA
- mozilla
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.1)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-693Protection Mechanism FailurePillar
- Data version
- 5.2
- Document digest
- 39c24d9c1962fbbde6a5c088a16e32f986d6b1f41bb7cbb573784beb4505b1c5
05 Affected products
06 References
- bugzilla.mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=1999257
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-01/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-02/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-03/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-04/
- www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-05/
- access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-0877
- bugzilla.redhat.comRHBZ#2428969https://bugzilla.redhat.com/show_bug.cgi?id=2428969
- security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0877.json
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2231
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2271
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2286
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:0667
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2220
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2074
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1471
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2073
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1461
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2070
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1487
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2069
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1462
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2047
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1413
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2044
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1415
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2041
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1414
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:2043
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:1320
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:0694
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:0924
07 Fixed in
AlmaLinux 8
- firefox Fixed in 140.7.0-1.el8_10.alma.1
- thunderbird Fixed in 140.7.0-1.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 140.7.0-1.el9_7.alma.1
- firefox-x11 Fixed in 140.7.0-1.el9_7.alma.1
- thunderbird Fixed in 140.7.0-1.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 140.7.0-1.el10_1
- thunderbird Fixed in 140.7.0-1.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 140.7.0-1.el8_10.alma.1
- thunderbird Fixed in 140.7.0-1.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 140.7.0-1.el9_7.alma.1
- firefox-x11 Fixed in 140.7.0-1.el9_7.alma.1
- thunderbird Fixed in 140.7.0-1.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 140.7.0-1.el10_1
- thunderbird Fixed in 140.7.0-1.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 140.7.0esr-1~deb12u1
- thunderbird Fixed in 1:140.7.0esr-1~deb12u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- firefox-esr Fixed in 140.7.0esr-1~deb13u1
- thunderbird Fixed in 1:140.7.0esr-1~deb13u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- firefox-esr Fixed in 140.7.0esr-1
- thunderbird Fixed in 1:140.7.0esr-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 Fixed in 1:140.7.1+build1-0ubuntu0.22.04.1
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.