Vulnerability details
CVE-2026-74989
Internally found bugs fixed in Firefox 154
CVSS 3.1
9.8Critical
Official description
Internally found bugs present in Firefox 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154 and Thunderbird 154.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.8Critical | 3.1 | CISA ADP / Vulnrichment (CISA-ADP) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| No product information recorded. | |||
References and advisories
4- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022257%2C2027351%2C2027380%2C2029289
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027388%2C2029750%2C2029794%2C2043298%2C2045126%2C2049810%2C2051741
- https://www.mozilla.org/security/advisories/mfsa2026-74/
- https://www.mozilla.org/security/advisories/mfsa2026-78/
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Details
- Published
- 2026-08-18
- Last updated
- 2026-10-28
- State
- Published
- Assigner (CNA)
- mozilla
Exploit prediction (EPSS)
0.57%
Probability of exploitation in 30 days
47.3%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer