Vulnerability RUSTSEC-2026-0507

Unknown

2 months ago

RRSIG signer name was not checked against the zone of the signed records

>=0.0.0-0 <0.26.2

Summary

RRSIG signer name was not checked against the zone of the signed records

Details

DNSSEC validation checked an RRset against the DNSKEYs of whatever zone was named in the RRSIG's Signer's Name field. RFC 4035 section 5.3.1 requires that name to be the zone that contains the RRset, but this was not checked.

Anyone who controls a DNSSEC-signed zone, and can answer or modify DNS responses, can therefore sign records for names in an unrelated zone with their own keys and have the validator accept them as secure.

This affects DNSSEC validation through DnssecDnsHandle (resolver, recursor and client) when built with dnssec-ring or dnssec-aws-lc-rs.

The fix ignores an RRSIG whose signer name is not the RRset's owner name or one of its ancestors. It is in 0.26.2.