ZDI-26-584: dnsmasq DNSSEC NSEC/NSEC3 Type Bitmap Processing Infinite Loop Denial-of-Service Vulnerability

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. Aug 13, 2026 · Catalog

   Detected

   This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of dnsmasq. Authentication is not required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2026-4890.

Sources

• CVE.orgVulnerability recordCVE-2026-4890

  Official CVE identifier

  cve.org
• FIRST EPSSExploitation probabilityCVE-2026-4890

  30-day exploitation probability 1.1%

  first.org
• Zero Day InitiativeCoordinated disclosureZDI-26-584

  This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of dnsmasq. Authentication is not required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2026-4890.

  zerodayinitiative.com