replay-attack

A replay attack occurs when an attacker intercepts and reuses valid authentication data, such as a login header or session token, to gain unauthorized access. On WindowsForum.com, discussions highlight real-world examples like the libsoup Digest authentication flaw (CVE-2026-3099), where missing nonce tracking allows captured Authorization headers to be replayed, bypassing security. Another example involves Cognex In‑Sight systems, where replayable authentication is listed among multiple vulnerabilities that raise risk for legacy industrial cameras. These threads emphasize how replay attacks undermine authentication mechanisms, turning a single captured credential into a reusable key. Understanding replay attack vectors is critical for securing web services, embedded systems, and enterprise networks against credential reuse and session hijacking.