Mitigation bypass in the DOM: Security component
Published Jan 13, 2026
8.1
HIGHCVSS 3.1
EPSS 0.48%
Description
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
Affected products
No data.
- < 115.32.0
- < 147.0
- ≥ 128.0 · < 140.7.0
- < 140.7.0
- < 147.0
No data.
Red Hat Enterprise Linux 10
firefox-0:140.7.0-1.el10_1
Fixed · RHSA-2026:2271
Red Hat Enterprise Linux 10
thunderbird-0:140.7.0-1.el10_1
Fixed · RHSA-2026:2286
Red Hat Enterprise Linux 10.0 Extended Update Support
firefox-0:140.7.0-1.el10_0
Fixed · RHSA-2026:2271
Red Hat Enterprise Linux 10.0 Extended Update Support
thunderbird-0:140.7.0-1.el10_0
Fixed · RHSA-2026:2286
Red Hat Enterprise Linux 7 Extended Lifecycle Support
firefox-0:140.7.0-1.el7_9
Fixed · RHSA-2026:2231
Red Hat Enterprise Linux 8
firefox-0:140.7.0-1.el8_10
Fixed · RHSA-2026:0667
Red Hat Enterprise Linux 8
thunderbird-0:140.7.0-1.el8_10
Fixed · RHSA-2026:2220
Red Hat Enterprise Linux 8.2 Advanced Update Support
firefox-0:140.7.0-1.el8_2
Fixed · RHSA-2026:2074
Red Hat Enterprise Linux 8.2 Advanced Update Support
thunderbird-0:140.7.0-1.el8_2
Fixed · RHSA-2026:1471
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
firefox-0:140.7.0-1.el8_4
Fixed · RHSA-2026:2073
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
thunderbird-0:140.7.0-1.el8_4
Fixed · RHSA-2026:1461
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
firefox-0:140.7.0-1.el8_4
Fixed · RHSA-2026:2073
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
thunderbird-0:140.7.0-1.el8_4
Fixed · RHSA-2026:1461
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
firefox-0:140.7.0-1.el8_6
Fixed · RHSA-2026:2070
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
thunderbird-0:140.7.0-1.el8_6
Fixed · RHSA-2026:1487
Red Hat Enterprise Linux 8.6 Telecommunications Update Service
firefox-0:140.7.0-1.el8_6
Fixed · RHSA-2026:2070
Red Hat Enterprise Linux 8.6 Telecommunications Update Service
thunderbird-0:140.7.0-1.el8_6
Fixed · RHSA-2026:1487
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
firefox-0:140.7.0-1.el8_6
Fixed · RHSA-2026:2070
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
thunderbird-0:140.7.0-1.el8_6
Fixed · RHSA-2026:1487
Red Hat Enterprise Linux 8.8 Telecommunications Update Service
firefox-0:140.7.0-1.el8_8
Fixed · RHSA-2026:2069
Red Hat Enterprise Linux 8.8 Telecommunications Update Service
thunderbird-0:140.7.0-1.el8_8
Fixed · RHSA-2026:1462
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
firefox-0:140.7.0-1.el8_8
Fixed · RHSA-2026:2069
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
thunderbird-0:140.7.0-1.el8_8
Fixed · RHSA-2026:1462
Red Hat Enterprise Linux 9
firefox-0:140.7.0-1.el9_7
Fixed · RHSA-2026:0694
Red Hat Enterprise Linux 9
thunderbird-0:140.7.0-1.el9_7
Fixed · RHSA-2026:0924
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
firefox-0:140.7.0-1.el9_0
Fixed · RHSA-2026:2047
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
thunderbird-0:140.7.0-1.el9_0
Fixed · RHSA-2026:1413
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
firefox-0:140.7.0-1.el9_2
Fixed · RHSA-2026:2044
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
thunderbird-0:140.7.0-1.el9_2
Fixed · RHSA-2026:1415
Red Hat Enterprise Linux 9.4 Extended Update Support
firefox-0:140.7.0-1.el9_4
Fixed · RHSA-2026:2041
Red Hat Enterprise Linux 9.4 Extended Update Support
thunderbird-0:140.7.0-1.el9_4
Fixed · RHSA-2026:1414
Red Hat Enterprise Linux 9.6 Extended Update Support
firefox-0:140.7.0-1.el9_6
Fixed · RHSA-2026:2043
Red Hat Enterprise Linux 9.6 Extended Update Support
thunderbird-0:140.7.0-2.el9_6
Fixed · RHSA-2026:1320
Red Hat Enterprise Linux 10
rhel10/firefox-flatpak
Affected
Red Hat Enterprise Linux 10
rhel10/thunderbird-flatpak
Affected
Red Hat Enterprise Linux 6
firefox
Out of support scope
Red Hat Enterprise Linux 6
thunderbird
Out of support scope
Red Hat Enterprise Linux 7
thunderbird
Out of support scope
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | firefox-0:140.7.0-1.el10_1 | Fixed | RHSA-2026:2271 |
| Red Hat Enterprise Linux 10 | thunderbird-0:140.7.0-1.el10_1 | Fixed | RHSA-2026:2286 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | firefox-0:140.7.0-1.el10_0 | Fixed | RHSA-2026:2271 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | thunderbird-0:140.7.0-1.el10_0 | Fixed | RHSA-2026:2286 |
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | firefox-0:140.7.0-1.el7_9 | Fixed | RHSA-2026:2231 |
| Red Hat Enterprise Linux 8 | firefox-0:140.7.0-1.el8_10 | Fixed | RHSA-2026:0667 |
| Red Hat Enterprise Linux 8 | thunderbird-0:140.7.0-1.el8_10 | Fixed | RHSA-2026:2220 |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | firefox-0:140.7.0-1.el8_2 | Fixed | RHSA-2026:2074 |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | thunderbird-0:140.7.0-1.el8_2 | Fixed | RHSA-2026:1471 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | firefox-0:140.7.0-1.el8_4 | Fixed | RHSA-2026:2073 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | thunderbird-0:140.7.0-1.el8_4 | Fixed | RHSA-2026:1461 |
| Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | firefox-0:140.7.0-1.el8_4 | Fixed | RHSA-2026:2073 |
| Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | thunderbird-0:140.7.0-1.el8_4 | Fixed | RHSA-2026:1461 |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | firefox-0:140.7.0-1.el8_6 | Fixed | RHSA-2026:2070 |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | thunderbird-0:140.7.0-1.el8_6 | Fixed | RHSA-2026:1487 |
| Red Hat Enterprise Linux 8.6 Telecommunications Update Service | firefox-0:140.7.0-1.el8_6 | Fixed | RHSA-2026:2070 |
| Red Hat Enterprise Linux 8.6 Telecommunications Update Service | thunderbird-0:140.7.0-1.el8_6 | Fixed | RHSA-2026:1487 |
| Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions | firefox-0:140.7.0-1.el8_6 | Fixed | RHSA-2026:2070 |
| Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions | thunderbird-0:140.7.0-1.el8_6 | Fixed | RHSA-2026:1487 |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service | firefox-0:140.7.0-1.el8_8 | Fixed | RHSA-2026:2069 |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service | thunderbird-0:140.7.0-1.el8_8 | Fixed | RHSA-2026:1462 |
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | firefox-0:140.7.0-1.el8_8 | Fixed | RHSA-2026:2069 |
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | thunderbird-0:140.7.0-1.el8_8 | Fixed | RHSA-2026:1462 |
| Red Hat Enterprise Linux 9 | firefox-0:140.7.0-1.el9_7 | Fixed | RHSA-2026:0694 |
| Red Hat Enterprise Linux 9 | thunderbird-0:140.7.0-1.el9_7 | Fixed | RHSA-2026:0924 |
| Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions | firefox-0:140.7.0-1.el9_0 | Fixed | RHSA-2026:2047 |
| Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions | thunderbird-0:140.7.0-1.el9_0 | Fixed | RHSA-2026:1413 |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | firefox-0:140.7.0-1.el9_2 | Fixed | RHSA-2026:2044 |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | thunderbird-0:140.7.0-1.el9_2 | Fixed | RHSA-2026:1415 |
| Red Hat Enterprise Linux 9.4 Extended Update Support | firefox-0:140.7.0-1.el9_4 | Fixed | RHSA-2026:2041 |
| Red Hat Enterprise Linux 9.4 Extended Update Support | thunderbird-0:140.7.0-1.el9_4 | Fixed | RHSA-2026:1414 |
| Red Hat Enterprise Linux 9.6 Extended Update Support | firefox-0:140.7.0-1.el9_6 | Fixed | RHSA-2026:2043 |
| Red Hat Enterprise Linux 9.6 Extended Update Support | thunderbird-0:140.7.0-2.el9_6 | Fixed | RHSA-2026:1320 |
| Red Hat Enterprise Linux 10 | rhel10/firefox-flatpak | Affected | n/a |
| Red Hat Enterprise Linux 10 | rhel10/thunderbird-flatpak | Affected | n/a |
| Red Hat Enterprise Linux 6 | firefox | Out of support scope | n/a |
| Red Hat Enterprise Linux 6 | thunderbird | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | thunderbird | Out of support scope | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
References (37)
- https://access.redhat.com/errata/RHSA-2026:0667
- https://access.redhat.com/errata/RHSA-2026:0694
- https://access.redhat.com/errata/RHSA-2026:0924
- https://access.redhat.com/errata/RHSA-2026:1320
- https://access.redhat.com/errata/RHSA-2026:1413
- https://access.redhat.com/errata/RHSA-2026:1414
- https://access.redhat.com/errata/RHSA-2026:1415
- https://access.redhat.com/errata/RHSA-2026:1461
- https://access.redhat.com/errata/RHSA-2026:1462
- https://access.redhat.com/errata/RHSA-2026:1471
- https://access.redhat.com/errata/RHSA-2026:1487
- https://access.redhat.com/errata/RHSA-2026:2041
- https://access.redhat.com/errata/RHSA-2026:2043
- https://access.redhat.com/errata/RHSA-2026:2044
- https://access.redhat.com/errata/RHSA-2026:2047
- https://access.redhat.com/errata/RHSA-2026:2069
- https://access.redhat.com/errata/RHSA-2026:2070
- https://access.redhat.com/errata/RHSA-2026:2073
- https://access.redhat.com/errata/RHSA-2026:2074
- https://access.redhat.com/errata/RHSA-2026:2220
- https://access.redhat.com/errata/RHSA-2026:2231
- https://access.redhat.com/errata/RHSA-2026:2271
- https://access.redhat.com/errata/RHSA-2026:2286
- https://access.redhat.com/security/cve/CVE-2026-0877 Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1999257 Permissions Required
- https://bugzilla.redhat.com/show_bug.cgi?id=2428969 Issue Tracking
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-2339 Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-0877
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0877.json
- https://www.cve.org/CVERecord?id=CVE-2026-0877
- https://www.mozilla.org/security/advisories/mfsa2026-01/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-02/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-03/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-03/#CVE-2026-0877
- https://www.mozilla.org/security/advisories/mfsa2026-04/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-05/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-05/#CVE-2026-0877
Change history (0)
No recorded changes yet.