Memory safety bugs fixed in Firefox 138 and Thunderbird 138
Summary
| CVE | CVE-2025-4092 |
|---|---|
| State | PUBLISHED |
| Assigner | mozilla |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2025-04-29 14:15:35 UTC |
| Updated | 2026-04-13 15:17:01 UTC |
| Description | Memory safety bugs present in Firefox 137 and Thunderbird 137. 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 138 and Thunderbird 138. |
Risk And Classification
Primary CVSS: v3.1 6.5 MEDIUM from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS: 0.002820000 probability, percentile 0.516070000 (date 2026-04-15)
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 | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Mozilla | Firefox | All | All | All | All |
| Application | Mozilla | Thunderbird | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Mozilla | Firefox | unaffected 138 * rpm | Not specified |
| CNA | Mozilla | Thunderbird | unaffected 138 * rpm | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.mozilla.org/buglist.cgi | [email protected] | bugzilla.mozilla.org | Broken Link |
| www.mozilla.org/security/advisories/mfsa2025-31 | [email protected] | www.mozilla.org | Vendor Advisory |
| www.mozilla.org/security/advisories/mfsa2025-28 | [email protected] | www.mozilla.org | Vendor Advisory |
| 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: Randell Jesup, Jens Stutte, and the Mozilla Fuzzing Team (en)
There are currently no legacy QID mappings associated with this CVE.