curl: CVE-2026-8927: env-set cross-proxy Digest auth state leak

AI-assisted preparation note I used AI assistance to help structure and format this report, but the technical findings, PoC, and verification results are based on local testing against curl/libcurl 8.20.0. Summary I found a possible incomplete-fix variant of CVE-2026-7168 in libcurl 8.20.0. The...

libcurl 7.12.0 < 8.20.0 Cross-Proxy Digest Auth State Leak

The version of libcurl installed on the remote host is 7.12.0 prior to 8.20.0. It is, therefore, affected by a cross-proxy digest auth state leak vulnerability: - libcurl improperly handles Digest authentication headers when reusing handles across different HTTP proxies. When a client switches fr...