Vulnerability RUSTSEC-2026-0489

When an SVCB or HTTPS record is parsed from its text (zone file) form, surrounding double quotes are removed from each service parameter value by checking that the value starts and ends with " and slicing off the first and last character. A value that is a single " (for example alpn=") passes that check, and the slice [1..0] panics.

Code that parses zone files or record text from an untrusted source can be made to panic, which is a denial of service. Records decoded from the DNS wire format are not parsed this way.

The fix rejects a lone quote character with a parse error before the slice. It is in 0.26.2.