CVE-2026-8962

Description

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Overview

State: PUBLISHED
Assigner (CNA): mozilla
CVSS severity: high
CVSS score: 8.1 / 10
CVSS vector: AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Effective score: 8.1 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-05-19
Published: 2026-05-19 12:29 UTC
Last updated: 2026-05-20 15:46 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/8xxx/CVE-2026-8962.json
Linked Threat: CVE-2026-8962 — CVE-2026-8962

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-05-19 14:16:52 UTC
NVD last modified: 2026-05-20 17:56:52 UTC
NVD CVSS v3.1: 8.1 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Exploitability subscore: 2.8 / 10
Impact subscore: 5.2 / 10
EPSS score: 0.0004 (probability of exploitation in next 30 days)
EPSS percentile: 13.59% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD-assigned CWE(s): CWE-693 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-30911
Assigner: mozilla
Published: May 19, 2026, 12:29:59 PM
Updated: May 20, 2026, 3:46:25 PM
EUVD base score (CVSS 3.1): 8.1 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EUVD-reported EPSS: 0.0500
Aliases: GHSA-93x2-246x-h3jh

ENISA description: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

EUVD references (5)

Affected products (2)

Vendor	Product	Versions	Platforms
Mozilla	Firefox	`140.11` (unaffected), `151` (unaffected)	—
Mozilla	Thunderbird	`140.11` (unaffected), `151` (unaffected)	—

Affected products — CPE 2.3 (4) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*

Vendor references (5)

References embedded in the original CVE record by the assigning CNA.

Web references (14)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

http://www.mozilla.org/security/announce/2026/mfsa2026-51.html rapid7:www.mozilla.org
http://www.mozilla.org/security/announce/2026/mfsa2026-48.html rapid7:www.mozilla.org
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-30911 rapid7:euvd.enisa.europa.eu
http://cwe.mitre.org/data/definitions/693.html rapid7:cwe.mitre.org
https://attackerkb.com/topics/CVE-2026-8962 rapid7:attackerkb.com
http://www.mozilla.org/security/announce/2026/mfsa2026-46.html rapid7:www.mozilla.org
https://www.first.org/epss/ tenable:www.first.org
https://www.mozilla.org/security/advisories/mfsa2026-46/ tenable:www.mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-48/ tenable:www.mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-50/ tenable:www.mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-51/ tenable:www.mozilla.org
https://bugzilla.mozilla.org/show_bug.cgi?id=2004804 tenable:bugzilla.mozilla.org
https://nvd.nist.gov/vuln/detail/CVE-2026-8962 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-8962 tenable:www.cve.org

NVD-tagged references (5)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://bugzilla.mozilla.org/show_bug.cgi?id=2004804 security@mozilla.org Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-46/ security@mozilla.org Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-48/ security@mozilla.org Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-50/ security@mozilla.org Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-51/ security@mozilla.org Vendor Advisory

Remediations (14)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

CVE-2026-8962 - Vulnerability Details - OpenCVE

web:app.opencve.io

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

2026-05-23 22:18 UTC
CVE-2026-8962 - Mitigation bypass in the DOM: Security component

web:cvefeed.io

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

2026-05-23 22:18 UTC
CVE-2026-8962 - Unknown Severity Vulnerability | CVEInfo.com

web:cveinfo.com

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11....

2026-05-23 22:18 UTC
CISA Warns of Exploited Microsoft Defender 0-Day Flaws

web:cyberpress.org

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .

2026-05-23 22:18 UTC
CVE-2026-8962 - Exploits & Severity - Feedly

web:feedly.com

Timeline Highlight Events CVE Assignment NVD published the first details for CVE-2026-8962 May 19, 2026 at 7:16 AM Vendor Advisory GitHub Advisories released a security advisory.

2026-05-23 22:18 UTC
Nvd - Cve-2026-8962

web:nvd.nist.gov

An official website of the United States government Here's how you know

2026-05-23 22:18 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-05-23 22:18 UTC
CVE-2026-8962 : Mitigation Bypass in the Security Component of Firefox ...

web:securityvulnerability.io

Learn about a significant mitigation bypass vulnerability affecting Firefox products. Key info about CVE-2026-8962 .

2026-05-23 22:18 UTC
CVE-2026-8962 | Ubuntu

web:ubuntu.com

Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things.

2026-05-23 22:18 UTC
CVE-2026-8962 - Mitigation bypass in the DOM:

web:www.nmmapper.com

cve details for CVE-2026-8962 - Mitigation bypass in the DOM: viewing details and related vulnerabilities.

2026-05-23 22:18 UTC
Microsoft and Adobe Patch Tuesday, April 2026 Security Update Review

web:blog.qualys.com

With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.

2026-05-26 02:58 UTC
Mitigation bypass in the DOM: Security component. This...

web:github.com

Description Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151 and Firefox ESR 140.11.

2026-05-26 02:58 UTC
Vulnerability Mitigation vs. Remediation: What Is the Difference?

web:virsec.com

In one of them, mitigation is a form of remediation . In another, it's a contrasting concept. However, the distinction between vulnerability mitigation and remediation is not just semantic; it's operational. Remediation offers a definitive, long-term vulnerability fix , but its time and resource demands make it insufficient on its own.

2026-05-26 02:58 UTC
Vulnerability Remediation vs. Mitigation: What are the Differences ...

web:www.secure.com

Learn the difference between vulnerability remediation and mitigation , and how a risk-based strategy can strengthen your security posture.

2026-05-26 02:58 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-8962.json.

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