CVE-2026-8947

Description

Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Overview

State: PUBLISHED
Assigner (CNA): mozilla
CVSS severity: high
CVSS score: 7.3 / 10
CVSS vector: AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Effective score: 7.3 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-05-19
Published: 2026-05-19 12:29 UTC
Last updated: 2026-05-19 17:10 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/8xxx/CVE-2026-8947.json
Linked Threat: CVE-2026-8947 — CVE-2026-8947

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 14:16:50 UTC
NVD last modified: 2026-05-19 18:47:52 UTC
NVD CVSS v3.1: 7.3 / 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:L/I:L/A:L
Exploitability subscore: 3.9 / 10
Impact subscore: 3.4 / 10
EPSS score: 0.0005 (probability of exploitation in next 30 days)
EPSS percentile: 15.38% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD-assigned CWE(s): CWE-416 (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-2026-30896
Assigner: mozilla
Published: May 19, 2026, 12:29:37 PM
Updated: May 19, 2026, 5:10:46 PM
EUVD base score (CVSS 3.1): 7.3 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EUVD-reported EPSS: 0.0700
Aliases: GHSA-6fhv-h367-4jc4

ENISA description: Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

EUVD references (6)

Affected products (2)

Vendor	Product	Versions	Platforms
Mozilla	Firefox	`115.36` (unaffected), `140.11` (unaffected), `151` (unaffected)	—
Mozilla	Thunderbird	`140.11` (unaffected), `151` (unaffected)	—

Affected products — CPE 2.3 (3) 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:*:*:*:*:*:*:*:*

Vendor references (6)

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

Web references (16)

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
http://www.mozilla.org/security/announce/2026/mfsa2026-47.html rapid7:www.mozilla.org
http://cwe.mitre.org/data/definitions/416.html rapid7:cwe.mitre.org
http://www.mozilla.org/security/announce/2026/mfsa2026-46.html rapid7:www.mozilla.org
https://attackerkb.com/topics/CVE-2026-8947 rapid7:attackerkb.com
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-30896 rapid7:euvd.enisa.europa.eu
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=2038439 tenable:bugzilla.mozilla.org
https://nvd.nist.gov/vuln/detail/CVE-2026-8947 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-8947 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/mfsa2026-47/ tenable:www.mozilla.org

NVD-tagged references (6)

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=2038439 security@mozilla.org Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-46/ security@mozilla.org Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-47/ 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-2026-8947 - Vulnerability Details - OpenCVE

web:app.opencve.io

Remediation No vendor fix or workaround currently provided. OpenCVE Recommended Actions Update Mozilla Firefox to version 151 or newer, or to latest ESR 115.36 or ESR 140.11. Update Mozilla Thunderbird to version 151 or newer, or to latest ESR 140.11. Enable automatic updates to ensure future patches are applied promptly.

2026-05-24 12:02 UTC
Nvd - Cve-2026-8947

web:nvd.nist.gov

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

2026-05-24 12:02 UTC
CVE-2026-8947 - security-tracker.debian.org

web:security-tracker.debian.org

Vulnerable and fixed packages The table below lists information on source packages.

2026-05-24 12:02 UTC
CVE-2026-8947 : Use-After-Free Vulnerability in Firefox and Firefox ESR ...

web:securityvulnerability.io

What is CVE-2026-8947 ? A use-after-free vulnerability exists in the DOM: Bindings (WebIDL) component of Firefox, which can potentially allow an attacker to execute arbitrary code.

2026-05-24 12:02 UTC
KB5090407 - Description of the security update for SQL Server 2019 CU32 ...

web:support.microsoft.com

Summary Improvements and fixes included in this update How to obtain and install the update How to obtain or download the latest cumulative update package for Linux More information File information Information about protection and security Summary This security update contains fixes and resolves vulnerabilities. To learn more about the vulnerabilities, see the following security advisories ...

2026-05-24 12:02 UTC
CVE-2026-8947 | 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.

2026-05-24 12:02 UTC
February's Patch Tuesday release fixes 59 flaws ... - Computerworld

web:www.computerworld.com

Each month, the team at Readiness analyzes the latest Patch Tuesday updates from Microsoft and provides detailed, actionable testing guidance. The company's Patch Tuesday release for February ...

2026-05-24 12:02 UTC
Security Vulnerabilities fixed in Firefox ESR 140.11 — Mozilla

web:www.mozilla.org

Mozilla Foundation Security Advisory 2026 -48 Security Vulnerabilities fixed in Firefox ESR 140.11 Announced May 19, 2026 Impact high Products Firefox ESR Fixed in Firefox ESR 140.11 # CVE - 2026 -8946: Incorrect boundary conditions in the Audio/Video: Web Codecs component Reporter zx Impact high References Bug 2029070 # CVE - 2026 -8388: Incorrect boundary conditions in the JavaScript Engine: JIT ...

2026-05-24 12:02 UTC
Microsoft fixes 167 security flaws in April, second biggest Patch ...

web:www.pcworld.com

This month's Patch Tuesday includes an actively exploited Office zero-day vulnerability and several critical RCE bugs in Windows and Remote Desktop.

2026-05-24 12:02 UTC
CVE-2026-8947 - High Vulnerability - TheHackerWire

web:www.thehackerwire.com

How severe is CVE-2026-8947 ? What Mozilla products are affected by CVE-2026-8947 ? How do I fix or mitigate CVE-2026-8947 ? When was CVE-2026-8947 disclosed?

2026-05-24 12:02 UTC
CVE-2026-8947 - Exploits & Severity - Feedly

web:feedly.com

May 19, 2026 at 7:05 AM / VulDB Recent Entries CVE Assignment NVD published the first details for CVE-2026-8947 May 19, 2026 at 7:16 AM CVSS A CVSS base score of 7.3 has been assigned.

2026-05-26 02:58 UTC
SecuriTricks - CVE-2026-8947 - 7.3/10

web:securitricks.com

CVE CVE-2026-8947 - Score : 7.3 - Source : security@mozilla.org - Description : Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

2026-05-26 02:58 UTC
Microsoft Confirms Active 0-Day Exploit—Check Emergency Mitigation

web:www.forbes.com

Updated May 17: This article, originally published May 16, has been updated to include further details on the emergency mitigation process recommended after the CVE - 2026 -42897 Microsoft Exchange ...

2026-05-26 02:58 UTC
CVE-2026-8947 Common Vulnerabilities and Exposures | SUSE

web:www.suse.com

Secure your Linux systems from CVE-2026-8947 . Stay ahead of potential threats with the latest security updates from SUSE.

2026-05-26 02:58 UTC

AI Forensic Analysis

Only Available for Registered Users. Sign in to view.

Raw JSON

The full cvelistV5 record. Download as CVE-2026-8947.json.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "LOW",
              "baseScore": 7.3,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "LOW",
              "integrityImpact": "LOW",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-8947",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-19T14:14:49.904157Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-416",
                "description": "CWE-416 Use After Free",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-19T14:15:12.387Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Firefox",
          "vendor": "Mozilla",
          "versions": [
            {
              "lessThanOrEqual": "115.*",
              "status": "unaffected",
              "version": "115.36",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "140.*",
              "status": "unaffected",
              "version": "140.11",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "151",
              "versionType": "rpm"
            }
          ]
        },
        {
          "product": "Thunderbird",
          "vendor": "Mozilla",
          "versions": [
            {
              "lessThanOrEqual": "140.*",
              "status": "unaffected",
              "version": "140.11",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "151",
              "versionType": "rpm"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Satoki Tsuji"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11."
            }
          ],
          "value": "Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-19T17:10:46.663Z",
        "orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
        "shortName": "mozilla"
      },
      "references": [
        {
          "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2038439"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2026-46/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2026-47/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2026-48/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2026-50/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2026-51/"
        }
      ],
      "title": "Use-after-free in the DOM: Bindings (WebIDL) component"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
    "assignerShortName": "mozilla",
    "cveId": "CVE-2026-8947",
    "datePublished": "2026-05-19T12:29:37.800Z",
    "dateReserved": "2026-05-19T12:29:37.072Z",
    "dateUpdated": "2026-05-19T17:10:46.663Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}