JIT miscompilation in the JavaScript: WebAssembly component
Summary
| CVE | CVE-2026-12321 |
|---|---|
| State | PUBLISHED |
| Assigner | mozilla |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-16 13:16:32 UTC |
| Updated | 2026-06-16 17:16:37 UTC |
| Description | JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 152 and Thunderbird 152. |
Risk And Classification
Primary CVSS: v3.1 5.4 MEDIUM from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Problem Types: CWE-670 | CWE-670 CWE-670 Always-Incorrect Control Flow Implementation
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Mozilla | Firefox | unaffected 152 * rpm | Not specified |
| CNA | Mozilla | Thunderbird | unaffected 152 * rpm | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.mozilla.org/show_bug.cgi | [email protected] | bugzilla.mozilla.org | |
| www.mozilla.org/security/advisories/mfsa2026-57 | [email protected] | www.mozilla.org | |
| www.mozilla.org/security/advisories/mfsa2026-60 | [email protected] | www.mozilla.org | |
| 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: JunYoung Park (en)
There are currently no legacy QID mappings associated with this CVE.