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CVE-2026-93009EUVD-2026-112826GHSA-6QRC-RPQW-59WP

Dnsmasq: dnsmasq: heap out-of-bounds read in dhcpv6 option 39 fqdn decoder

Published
Last modified
published
Not listed in CISA KEV
None on Exploit-DB, Metasploit or GitHub

Summary

Dnsmasq, a lightweight DNS and DHCP server commonly used on Linux systems and network devices, is affected. An attacker on the local network could send a single crafted DHCPv6 packet to cause a one-byte out-of-bounds memory read, though the extra data is not exposed or logged and no crash has been demonstrated.

Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.

Read the original description

A flaw was found in dnsmasq. The DHCPv6 client hostname parser can read one byte past the end of a crafted FQDN option because it checks the next label length before confirming the pointer is still inside the option. An attacker on the local network can trigger this with a single DHCPv6 packet. The extra byte is not returned to the client or logged, and no crash has been demonstrated.

Timeline

  1. CVE published
  2. First seen by cve.now
  3. Record last updated

Affected versions

  • rhceph/alloy-rhel10

    Version range not reported

  • dnsmasq

    Version range not reported

  • dnsmasq

    Version range not reported

  • dnsmasq

    Version range not reported

  • dnsmasq

    Version range not reported

  • dnsmasq

    Version range not reported

  • openshift4/ose-baremetal-runtimecfg-rhel8

    Version range not reported

  • openshift4/ose-baremetal-runtimecfg-rhel9

    Version range not reported

  • openshift/ose-rhel-coreos-8

    Version range not reported

  • openshift/ose-rhel-coreos-9

    Version range not reported

  • openshift5/ose-baremetal-runtimecfg-rhel9

    Version range not reported

  • openshift/ose-rhel-coreos-9

    Version range not reported

  • dnsmasq

    Version range not reported

  • rhoso-operators/infra-rhel9-operator

    Version range not reported

References 2

access.redhat.com

bugzilla.redhat.com