CVE-2026-43971

Improper Encoding or Escaping of Output vulnerability in ninenines cowlib allows Link header directive smuggling via unescaped special characters in cowlink:link/1. cowlink:dolink/1 in cowlib interpolates the target URI, rel value, and attribute keys directly into the serialized Link: header valu...

CVE-2026-43971

In cowlib (from 2.9.0 onward), cow_link:do_link/1 interpolates target URI, rel value, and attribute keys directly into the serialized Link header without escaping or token-grammar validation. An attacker controlling these fields can inject > to close the URI slot, "/\ to break the rel string, ...