CVE-2026-12289
Published: 16 June 2026
Summary
CVE-2026-12289 is a high-severity Improper Privilege Management (CWE-269) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 31.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-37080
Vulnerability details
Privilege escalation in the Graphics: WebRender component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Explicit privilege escalation vulnerability (CWE-269) directly matches T1068 Exploitation for Privilege Escalation.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Policy addresses roles, responsibilities, and privilege management to prevent improper privilege assignments.
Access supervision ensures privileges are assigned and managed without improper escalation or retention.
Assigning group/role memberships and access authorizations (privileges) while reviewing accounts addresses improper privilege management.
The control requires explicit definition of separated access authorizations, making incorrect privilege assignments that bundle conflicting duties harder to implement.
Implements core proper privilege management by restricting to only required rights.
Enforces proper privilege management by requiring all decisions through the verified reference monitor.
Policy requires training on privilege management and least privilege, making it harder to exploit improper privilege management weaknesses.
Training covers proper privilege management practices, making incorrect privilege assignments less likely.