What is the CVSS score of CVE-2026-8957?

CVE-2026-8957 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of Mozilla Firefox are affected by CVE-2026-8957?

Mozilla Firefox privilege escalation vulnerability (CVE-2026-8957) could expose organizational data if employees are tricked into viewing malicious content, potentially providing attackers access to…. A patch is available.

How to fix or mitigate CVE-2026-8957?

Within 24 hours: Inventory current Firefox and Firefox ESR versions across the organization. Within 7 days: Deploy Firefox 151+ and Firefox ESR 140.11+ through standard patch management; prioritize high-privilege user endpoints. Within 30 days: Verify patching completion across all instances and confirm zero vulnerable versions remain.

Mozilla Firefox CVE-2026-8957

EUVD-2026-30908 HIGH

Improper Privilege Management (CWE-269)

2026-05-19 mozilla

GHSA-83v4-m9qr-xgp9

Mozilla Privilege Escalation Red Hat Suse

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

SUSE

HIGH

qualitative

Red Hat

6.1 MEDIUM

qualitative

Primary rating from NVD.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

May 20, 2026 - 17:24 vuln.today

Severity Changed

May 20, 2026 - 17:22 NVD

MEDIUM HIGH

CVSS changed

May 20, 2026 - 17:22 NVD

6.5 (MEDIUM) 8.8 (HIGH)

CVE Published

May 19, 2026 - 12:29 nvd

UNKNOWN (no severity yet)

DescriptionCVE.org

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

AnalysisAI

Privilege escalation in the Enterprise Policies component of Mozilla Firefox affects versions prior to Firefox 151 and Firefox ESR 140.11, allowing remote attackers who can convince a user to interact with crafted content to elevate privileges within the browser. No public exploit identified at time of analysis, and EPSS scoring places exploitation probability at just 0.03% (9th percentile). The vulnerability requires user interaction per the CVSS vector, which somewhat constrains real-world weaponization despite the high 8.8 CVSS score.

Technical ContextAI

Mozilla Firefox's Enterprise Policies component is an administrative subsystem used by organizations to enforce browser configuration, restrictions, and security controls across managed deployments via policies.json or platform-specific policy stores (Group Policy on Windows, configuration profiles on macOS). The root cause maps to CWE-269 (Improper Privilege Management), indicating that the Enterprise Policies code path fails to correctly assign, enforce, or validate privilege boundaries - likely permitting content or operations running at lower trust levels to influence or bypass policy-enforced privileges. Per the CPE (cpe:2.3:a:mozilla:firefox), all Firefox builds prior to the fixed versions are in scope, with separate advisories (MFSA2026-46/48/50/51) covering Firefox release, ESR, and potentially Thunderbird channels.

RemediationAI

Vendor-released patch: upgrade to Firefox 151 or Firefox ESR 140.11 (or later) as confirmed in the CVE description and Mozilla advisories MFSA2026-46/48/50/51. Enterprise administrators using managed Firefox deployments should consult https://www.mozilla.org/security/advisories/mfsa2026-50/ and https://www.mozilla.org/security/advisories/mfsa2026-51/ to align ESR rollout with the 140.11 baseline. As a compensating control prior to patching, restrict users from visiting untrusted sites via web proxy categorization or DNS filtering since exploitation requires user interaction with attacker-controlled content; this reduces exposure but does not address policy-bypass scenarios from internal pages. Avoid disabling Enterprise Policies entirely as that removes the very security enforcement the organization depends on; instead prioritize rapid patch deployment through SCCM, Intune, or equivalent endpoint management.

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Vendor StatusVendor

SUSE

Severity: High

Product	Status
SUSE Linux Enterprise Server 12 SP5-LTSS	Fixed
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5	Fixed
openSUSE Tumbleweed	Fixed
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS	Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS	Affected

CVE-2026-8957 vulnerability details – vuln.today

Back

Mozilla Firefox CVE-2026-8957

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

RemediationAI

More in Mozilla

Same weakness CWE-269 – Improper Privilege Management

Same technique Privilege Escalation

Vendor StatusVendor

SUSE

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External POC / Exploit Code