Cyber Resilience

CVE-2026-8969

High

Published: 19 May 2026

Published
19 May 2026
Modified
20 May 2026
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score 0.0029 20.7th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-8969 is a high-severity Protection Mechanism Failure (CWE-693) vulnerability in Mozilla Firefox. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 20.7th 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

Vulnerability details

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
Why these techniques?

Mitigation bypass in browser DOM security component directly enables client-side exploitation and drive-by attacks via malicious web content.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-8962Same product: Mozilla Firefox
CVE-2026-6763Same product: Mozilla Firefox
CVE-2026-6774Same product: Mozilla Firefox
CVE-2026-2761Same product: Mozilla Firefox
CVE-2026-0877Same product: Mozilla Firefox
CVE-2025-1942Same product: Mozilla Firefox
CVE-2026-2805Same product: Mozilla Firefox
CVE-2025-1010Same product: Mozilla Firefox
CVE-2026-2797Same product: Mozilla Firefox
CVE-2025-8044Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 151.0.0
mozilla
thunderbird
≤ 151.0.0

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.

addresses: CWE-693

Implements a reliable, tamperproof protection mechanism whose completeness can be assured.

addresses: CWE-693

Procedures for training on protection mechanisms reduce the chance of protection mechanism failures being present or exploitable.

addresses: CWE-693

Documented procedures to implement assessment, authorization, and monitoring controls prevent these protection mechanisms from failing due to undefined processes.

addresses: CWE-693

Direct evaluation of whether controls produce desired security outcomes detects protection mechanism failures and enables remediation.

addresses: CWE-693

Requires assessment that protection mechanisms are correctly implemented and producing intended security outcomes.

addresses: CWE-693

The POA&M process ensures identified weaknesses in protection mechanisms are documented and scheduled for remediation, reducing the duration they remain exploitable.

addresses: CWE-693

Ongoing control assessments and analysis of monitoring data enable timely detection and response when protection mechanisms fail.

addresses: CWE-693

Impact analysis identifies changes that could weaken or disable existing protection mechanisms.

References