CVE-2026-12969
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.
Summary dbcve.org
An out-of-bounds read vulnerability exists in dnsmasq's find_soa() function where extract_name() is called with extrabytes=0 when parsing NS section records, 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 heap allocations.
Mitigation
Upgrade dnsmasq to the patched version that adds proper bounds validation in extract_name() to ensure sufficient bytes exist before reading fixed-length DNS record fields. As a defensive measure, restrict authoritative DNS servers that the dnsmasq instance accepts responses from to trusted sources.