A vulnerability in the Hickory proto library causes a panic when parsing malformed 'alpn' values in SVCB or HTTPS DNS record text forms. This occurs because the parser assumes the 'alpn' value is always well-formed and calls 'expect' on the result, leading to a panic on malformed inputs such as unbalanced quotes or invalid escapes. This can cause denial of service when parsing zone files or record text from untrusted sources. The issue does not affect records decoded from DNS wire format. A fix is available in version 0.26.2 that returns a parse error instead of panicking.