CVE-2026-8966

Description

Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

Overview

State: PUBLISHED
Assigner (CNA): mozilla
CVSS severity: high
CVSS score: 7.5 / 10
CVSS vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Effective score: 7.5 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-05-19
Published: 2026-05-19 12:30 UTC
Last updated: 2026-05-20 15:46 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/8xxx/CVE-2026-8966.json
Linked Threat: CVE-2026-8966 — CVE-2026-8966

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 14:16:53 UTC
NVD last modified: 2026-05-20 17:51:24 UTC
NVD CVSS v3.1: 7.5 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploitability subscore: 3.9 / 10
Impact subscore: 3.6 / 10
EPSS score: 0.0003 (probability of exploitation in next 30 days)
EPSS percentile: 9.17% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD-assigned CWE(s): CWE-200 (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-2026-30918
Assigner: mozilla
Published: May 19, 2026, 12:30:11 PM
Updated: May 20, 2026, 3:46:14 PM
EUVD base score (CVSS 3.1): 7.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EUVD-reported EPSS: 0.0400
Aliases: GHSA-wq4p-4w8c-6qcg

ENISA description: Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

EUVD references (3)

Affected products (2)

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

Affected products — CPE 2.3 (2) 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:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*

Vendor references (3)

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

Web references (11)

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/mfsa2026-50.html rapid7:www.mozilla.org
https://attackerkb.com/topics/CVE-2026-8966 rapid7:attackerkb.com
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-30918 rapid7:euvd.enisa.europa.eu
http://cwe.mitre.org/data/definitions/200.html rapid7:cwe.mitre.org
http://www.mozilla.org/security/announce/2026/mfsa2026-46.html rapid7:www.mozilla.org
https://www.cve.org/CVERecord?id=CVE-2026-8966 tenable:www.cve.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/mfsa2026-50/ tenable:www.mozilla.org
https://bugzilla.mozilla.org/show_bug.cgi?id=2025849 tenable:bugzilla.mozilla.org
https://nvd.nist.gov/vuln/detail/CVE-2026-8966 tenable:nvd.nist.gov

NVD-tagged references (3)

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=2025849 security@mozilla.org Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-46/ security@mozilla.org Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-50/ security@mozilla.org Vendor Advisory

Remediations (16)

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

CVE-2026-8966 - Vulnerability Details - OpenCVE

web:app.opencve.io

Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

2026-05-23 22:18 UTC
Update: Monthly Critical Security Patch Updates (CSPUs) Begin May 28 ...

web:blogs.oracle.com

As a follow-up to our recent post, Accelerating Vulnerability Detection and Response, Oracle is announcing the start date and cadence for monthly Critical Security Patch Updates (CSPUs). Beginning May 28, 2026 , Oracle will deliver a Critical Security Patch Update (CSPU) each month.

2026-05-23 22:18 UTC
CVE-2026-8966 | Security Details | Sonatype Guide

web:guide.sonatype.com

Technical security analysis for CVE-2026-8966 . CVSS 2.1 severity. View CVSS vectors, CWE classifications, and exploit maturity ratings.

2026-05-23 22:18 UTC
Patch Tuesday, May 2026 Edition - Krebs on Security

web:krebsonsecurity.com

Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.

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
Information Disclosure in Firefox IP Protection Component CVE-2026-8966

web:securityvulnerability.io

Learn about an information disclosure vulnerability affecting Firefox and its IP protection features. Key details on CVE-2026-8966 .

2026-05-23 22:18 UTC
February 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft's February 2026 Patch Tuesday addresses 59 CVEs , featuring six exploited vulnerabilities, three of which were publicly known, and five Critical vulnerabilities.

2026-05-23 22:18 UTC
January 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft has released security updates for 114 vulnerabilities, including three zero-days, plus eight critical CVEs in its January 2026 Patch Tuesday rollout.

2026-05-23 22:18 UTC
Oracle Critical Patch Update Advisory - April 2026

web:www.oracle.com

This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

2026-05-23 22:18 UTC
CVE-2026-8966 - High Vulnerability - TheHackerWire

web:www.thehackerwire.com

CVE-2026-8966 is a High severity vulnerability (CVSS 7.5). Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

2026-05-23 22:18 UTC
Windows Kerberos RC4 deprecation: what will break in Active ... - 4sysops

web:4sysops.com

Starting in April 2026 , Windows updates will change the default Kerberos ticket issuance behavior to AES-SHA1 for accounts without explicit encryption settings, while RC4 can still be used where explicitly enabled. This change, driven by CVE - 2026 -20833, affects every Windows Server environment where service accounts or devices still rely on RC4. Any service account, NAS device, or legacy ...

2026-05-26 02:58 UTC
Security Update Guide - Microsoft

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

2026-05-26 02:58 UTC
SecuriTricks - CVE-2026-8966 - 7.5/10

web:securitricks.com

CVE CVE-2026-8966 - Score : 7.5 - Source : security@mozilla.org - Description : Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

2026-05-26 02:58 UTC
Critical Patches Issued for Microsoft Products, April 14, 2026

web:www.cisecurity.org

<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...

2026-05-26 02:58 UTC
Emergency patch issued for Microsoft Office, 365 over hacking threat - MSN

web:www.msn.com

Original story: Microsoft has released an emergency patch for a vulnerability in the company's Office programs that's already being exploited by hackers.

2026-05-26 02:58 UTC
CVE-2026-8966 | Tenable®

web:www.tenable.com

Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

2026-05-26 02:58 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-8966.json.

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