CVE-2026-4890

Description

A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.

Overview

State: PUBLISHED
Assigner (CNA): certcc
CVSS severity: high
CVSS score: 7.5 / 10
CVSS vector: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Effective score: 7.5 / 10 HIGH source: CNA overview
MSRC score: 7.5 / 10 HIGH MS rating: Moderate
CWE(s): CWE-835: Loop with Unreachable Termination
Reserved: 2026-03-26
Published: 2026-05-11 18:47 UTC
Last updated: 2026-05-11 21:58 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/4xxx/CVE-2026-4890.json
Linked Threat: CVE-2026-4890 — CVE-2026-4890

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: 2026-05-11 18:16:41 UTC
NVD last modified: 2026-05-12 14:15:46 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:N/I:N/A:H
Exploitability subscore: 3.9 / 10
Impact subscore: 3.6 / 10
EPSS score: 0.0024 (probability of exploitation in next 30 days)
EPSS percentile: 47.02% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

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-2026-29152
Assigner: certcc
Published: May 11, 2026, 4:47:16 PM
Updated: May 20, 2026, 2:08:25 PM
EUVD base score (CVSS 3.1): 7.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EUVD-reported EPSS: 0.2400
Vendors: dnsmasq
Products: dnsmasq (2.93)

dnsmasq (2.92rel2)

dnsmasq (0 <2.92rel2)

ENISA description: A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.

EUVD references (6)

Microsoft Security Response Center MSRC

Microsoft's vendor-authoritative record from the Security Update Guide — its own CVSS score, impact, severity rating, exploit assessment, and KB-article fixes. Refreshed 2026-07-28 03:00 UTC (source: CVRF).

MS severity: Moderate
MS CVSS base score: 7.5 / 10 (temporal 6.9)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U
Release: 2026-May

Microsoft remediations / KB articles (2)

CBL-Mariner Releases — Vendor Fix / Security Update (fixed build 2.92-1)
https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade — None Available / CBL-Mariner Releases

Affected products (1)

Vendor	Product	Versions	Platforms
dnsmasq	dnsmasq	`2.92rel2` (affected)	—

Vendor references (6)

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

MITRE references (6) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

Web references (9)

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

None Available msrc
MSRC update guide: CVE-2026-4890 msrc
https://attackerkb.com/topics/CVE-2026-4890 rapid7:attackerkb.com
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-29152 rapid7:euvd.enisa.europa.eu
https://security.alpinelinux.org/vuln/CVE-2026-4890 rapid7:security.alpinelinux.org
https://www.first.org/epss/ tenable:www.first.org
https://kb.cert.org/vuls/id/471747 tenable:kb.cert.org
https://www.cve.org/CVERecord?id=CVE-2026-4890 tenable:www.cve.org
https://nvd.nist.gov/vuln/detail/CVE-2026-4890 tenable:nvd.nist.gov

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://github.com/NixOS/nixpkgs/pull/519082 cret@cert.org
https://github.com/NixOS/nixpkgs/pull/519093 cret@cert.org
https://github.com/pi-hole/FTL/releases/tag/v6.6.2 cret@cert.org
https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html cret@cert.org
https://thekelleys.org.uk/dnsmasq/CVE/ cret@cert.org
https://www.kb.cert.org/vuls/id/471747 cret@cert.org

Remediations (18)

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

Microsoft acknowledges May 2026 Windows 11 security update install ...

web:betanews.com

Another month, another update for Windows which is problematic. This time around, it is the May 2026 Windows 11 security update - or the KB5089549 update.

2026-05-23 21:01 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 21:01 UTC
Patch Tuesday, April 2026 Edition - Krebs on Security

web:krebsonsecurity.com

For a clickable, per- patch breakdown, check out the SANS Internet Storm Center Patch Tuesday roundup. Running into problems applying any of these updates?

2026-05-23 21:01 UTC
Nvd - Cve-2026-4890

web:nvd.nist.gov

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

2026-05-23 21:01 UTC
Oracle CPU April 2026: Delayed RUs & First Analysis

web:oradba.ch

19c 26ai cve oracle-cpu patch -management release-update security Oracle CPU April 2026 : Delayed RUs & First Analysis On April 21, 2026 , Oracle released the Critical Patch Update (CPU) for April 2026 — 481 new security fixes across the entire Oracle product stack. For Oracle Database, this means another round of mandatory patching.

2026-05-23 21:01 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 21:01 UTC
Android Security Bulletins - Android Open Source Project

web:source.android.com

This Section contains the available Android Security Bulletins, which provide fixes for possible issues affecting Android devices.

2026-05-23 21:01 UTC
2 New Microsoft Defender Zero-Days Exploited—Patch Now ... - Forbes

web:www.forbes.com

Microsoft has confirmed an emergency security update as CISA warns that two new Defender zero-days are being exploited by attackers.

2026-05-23 21:01 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 21:01 UTC
Microsoft Issues Massive Windows Patch for 160+ Bugs ... - TechRepublic

web:www.techrepublic.com

Microsoft's April 2026 Patch Tuesday fixes 165 vulnerabilities, including two zero-days, in one of the company's largest monthly security updates.

2026-05-23 21:01 UTC
Security Updates - Red Hat Customer Portal

web:access.redhat.com

Learn about our open source products, services, and company. You are here

2026-05-26 02:49 UTC
Google publishes exploit code threatening millions of Chromium ...

web:arstechnica.com

Google publishes exploit code threatening millions of Chromium users Google publishes exploit code before patch , reported 42 months earlier, is fixed.

2026-05-26 02:49 UTC
Security Advisory Bulletin 064 | Ubiquiti Community

web:community.ui.com

Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...

2026-05-26 02:49 UTC
Adobe Security Bulletins and Advisories

web:helpx.adobe.com

This page contains important information regarding security vulnerabilities that could affect specific versions of Adobe products. Use this information to take the prescribed corrective actions.

2026-05-26 02:49 UTC
NVD - Home

web:nvd.nist.gov

The NVD is the U.S. government repository of standards based vulnerability management data represented using the Security Content Automation Protocol (SCAP). This data enables automation of vulnerability management, security measurement, and compliance. The NVD includes databases of security checklist references, security-related software flaws, product names, and impact metrics. For ...

2026-05-26 02:49 UTC
Android Security Bulletin—May 2026 - Android Open Source Project

web:source.android.com

Android partners are encouraged to fix all issues in this bulletin and use the latest security patch level. Devices that use the 2026 -05-01 security patch level must include all issues associated with that security patch level, as well as fixes for all issues reported in previous security bulletins.

2026-05-26 02:49 UTC
Landing Page | ServiceNow Common Vulnerabilities & Exposures (CVE ...

web:support.servicenow.com

Overview The advisories below document publicly disclosed Common Vulnerabilities and Exposures ( CVEs ) in the Now Platform by ServiceNow. Because ServiceNow uses various methods to communicate vulnerability information, patches, and other fixes, customers should review family, security patch , and hotfix release notes, which are available at https://docs.servicenow.com, for a complete list of ...

2026-05-26 02:49 UTC
Fix list for IBM WebSphere Application Server traditional V9

web:www.ibm.com

IBM WebSphere Application Server traditional provides periodic fixes for the base and Network Deployment editions of release V9. The following is a complete listing of fixes for V9 with the most recent fix at the top.

2026-05-26 02:49 UTC

AI Forensic Analysis

Only Available for Registered Users. Sign in to view.

Raw JSON

The full cvelistV5 record. Download as CVE-2026-4890.json.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-4890",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-11T18:28:07.653867Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-11T18:28:11.342Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "dnsmasq",
          "vendor": "dnsmasq",
          "versions": [
            {
              "status": "affected",
              "version": "2.92rel2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-835: Loop with Unreachable Termination",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T19:58:36.052Z",
        "orgId": "37e5125f-f79b-445b-8fad-9564f167944b",
        "shortName": "certcc"
      },
      "references": [
        {
          "url": "https://www.kb.cert.org/vuls/id/471747"
        },
        {
          "url": "https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html"
        },
        {
          "url": "https://thekelleys.org.uk/dnsmasq/CVE/"
        },
        {
          "url": "https://github.com/NixOS/nixpkgs/pull/519093"
        },
        {
          "url": "https://github.com/NixOS/nixpkgs/pull/519082"
        },
        {
          "url": "https://github.com/pi-hole/FTL/releases/tag/v6.6.2"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "CVE-2026-4890",
      "x_generator": {
        "engine": "VINCE 3.0.39",
        "env": "prod",
        "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-4890"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b",
    "assignerShortName": "certcc",
    "cveId": "CVE-2026-4890",
    "datePublished": "2026-05-11T16:47:16.419Z",
    "dateReserved": "2026-03-26T13:05:10.729Z",
    "dateUpdated": "2026-05-11T19:58:36.052Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}