Cyber Posture

CVE-2026-8957

High

Published: 19 May 2026

Published
19 May 2026
Modified
20 May 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0003 8.7th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-8957 is a high-severity Improper Privilege Management (CWE-269) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).

Operationally, ranked at the 8.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense Details

Likely Mitigating ControlsAI

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.

addresses: CWE-269

Policy addresses roles, responsibilities, and privilege management to prevent improper privilege assignments.

addresses: CWE-269

Access supervision ensures privileges are assigned and managed without improper escalation or retention.

addresses: CWE-269

Assigning group/role memberships and access authorizations (privileges) while reviewing accounts addresses improper privilege management.

addresses: CWE-269

Enforces proper privilege management by requiring all decisions through the verified reference monitor.

addresses: CWE-269

By mandating division of duties across roles, the control enforces proper privilege management and prevents a single entity from controlling an entire sensitive process.

addresses: CWE-269

Implements core proper privilege management by restricting to only required rights.

addresses: CWE-269

Policy requires training on privilege management and least privilege, making it harder to exploit improper privilege management weaknesses.

addresses: CWE-269

Training covers proper privilege management practices, making incorrect privilege assignments less likely.

NVD Description

Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 140.11.0 · ≤ 151.0.0
mozilla
thunderbird
≤ 140.11 · ≤ 151.0.0

References