Telechat Review of draft-ietf-cellar-tags-25
review-ietf-cellar-tags-25-secdir-telechat-sethi-2026-05-03-00

I have reviewed this document as part of the security directorate's ongoing
effort to review all IETF documents being processed by the IESG. These comments
were written primarily for the benefit of the security area directors. Document
editors and WG chairs should treat these comments just like any other last-call
comments.

Since the last reviewed version (-19), the authors have added other specific
vectors of security issues such as string parsing risks and URL handling.
Implementations must strictly validate TagString inputs for UTF-8 correctness
and reasonable length limits to prevent vulnerabilities when reading strings
as-is or parsing specific technical tags. The authors also highlight that tags
containing URLs could be spoofed or altered to direct users to malicious
destinations.