What’s Vulnerable › Vulnerabilities

CVE-2026-12969: Dnsmasq: dnsmasq: out-of-bounds read in find_soa() due to missing extrabytes validation

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-23 · updated 2026-08-31
• Weakness: CWE-125

Description

An out-of-bounds read vulnerability exists in dnsmasq's find_soa() function in src/rfc1035.c. When parsing NS section records, extract_name() is called with extrabytes=0, failing to validate that 10 additional bytes exist for fixed-length DNS record fields. A remote attacker controlling a DNS zone can exploit this via a crafted NXDOMAIN response to cause a 10-byte heap out-of-bounds read, potentially accessing stale data from prior transactions.

Affected products

• Red Hat Enterprise Linux: 10.0
• Simon Kelley dnsmasq: before 2.93 — fixed in 2.93

How to fix

Upgrade to a fixed version: Simon Kelley dnsmasq 2.93. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/security/cve/CVE-2026-12969
• https://bugzilla.redhat.com/show_bug.cgi?id=2491663

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