Memory safety bugs fixed in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147
Summary
| CVE | CVE-2026-0891 |
|---|---|
| State | PUBLISHED |
| Assigner | mozilla |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-01-13 14:16:39 UTC |
| Updated | 2026-07-15 02:17:59 UTC |
| Description | Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7. |
Risk And Classification
Primary CVSS: v3.1 8.1 HIGH from ADP
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.004140000 probability, percentile 0.335930000 (date 2026-07-17)
Problem Types: CWE-119 | CWE-119 CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | ADP | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Mozilla | Firefox | All | All | All | All |
| Application | Mozilla | Firefox | All | All | All | All |
| Application | Mozilla | Thunderbird | All | All | All | All |
| Application | Mozilla | Thunderbird | All | All | All | All |
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:2231 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:0924 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:0694 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2041 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2043 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2047 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2073 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:1471 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:1415 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:1413 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:1487 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2286 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2220 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| www.mozilla.org/security/advisories/mfsa2026-01 | [email protected] | www.mozilla.org | Vendor Advisory |
| www.mozilla.org/security/advisories/mfsa2026-03 | [email protected] | www.mozilla.org | Vendor Advisory |
| www.mozilla.org/security/advisories/mfsa2026-04 | [email protected] | www.mozilla.org | Vendor Advisory |
| www.mozilla.org/security/advisories/mfsa2026-05 | [email protected] | www.mozilla.org | Vendor Advisory |
| access.redhat.com/errata/RHSA-2026:1462 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:1461 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0891.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2069 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2271 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.mozilla.org/buglist.cgi | [email protected] | bugzilla.mozilla.org | Broken Link |
| access.redhat.com/errata/RHSA-2026:1320 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:1414 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:0667 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-0891 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2074 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2070 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:2044 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Andrew McCreight, Dennis Jackson and the Mozilla Fuzzing Team (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-01-13T14:01:25.941Z | Reported to Red Hat. |
| ADP | 2026-01-13T13:30:59.454Z | Made public. |
Solutions
ADP: RHSA-2026:2231: Red Hat Enterprise Linux Server (v. 7 ELS)
ADP: RHSA-2026:2271: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream EUS (v. 10.0)
ADP: RHSA-2026:2286: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream EUS (v. 10.0)
ADP: RHSA-2026:0667: Red Hat Enterprise Linux AppStream (v. 8)
ADP: RHSA-2026:2220: Red Hat Enterprise Linux AppStream (v. 8)
ADP: RHSA-2026:2074: Red Hat Enterprise Linux AppStream AUS (v. 8.2)
ADP: RHSA-2026:1471: Red Hat Enterprise Linux AppStream AUS (v. 8.2)
ADP: RHSA-2026:2073: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
ADP: RHSA-2026:1461: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
ADP: RHSA-2026:2070: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream E4S (v.8.6), Red Hat Enterprise Linux AppStream TUS (v.8.6)
ADP: RHSA-2026:1487: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream E4S (v.8.6), Red Hat Enterprise Linux AppStream TUS (v.8.6)
ADP: RHSA-2026:2069: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8)
ADP: RHSA-2026:1462: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8)
ADP: RHSA-2026:2047: Red Hat Enterprise Linux AppStream E4S (v.9.0)
ADP: RHSA-2026:1413: Red Hat Enterprise Linux AppStream E4S (v.9.0)
ADP: RHSA-2026:2044: Red Hat Enterprise Linux AppStream E4S (v.9.2)
ADP: RHSA-2026:1415: Red Hat Enterprise Linux AppStream E4S (v.9.2)
ADP: RHSA-2026:2041: Red Hat Enterprise Linux AppStream EUS (v.9.4)
ADP: RHSA-2026:1414: Red Hat Enterprise Linux AppStream EUS (v.9.4)
ADP: RHSA-2026:2043: Red Hat Enterprise Linux AppStream EUS (v.9.6)
ADP: RHSA-2026:1320: Red Hat Enterprise Linux AppStream EUS (v.9.6)
ADP: RHSA-2026:0694: Red Hat Enterprise Linux AppStream (v. 9)
ADP: RHSA-2026:0924: Red Hat Enterprise Linux AppStream (v. 9)