CWE-294: Authentication Bypass by Capture-replay
A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).
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Overview
Capture-replay attacks are common and can be difficult to defeat without cryptography. They are a subset of network injection attacks that rely on observing previously-sent valid commands, then changing them slightly if necessary and resending the same commands to the server.
Real-world CVEs
272 recorded CVEs are caused by CWE-294 (Authentication Bypass by Capture-replay). The highest-severity and most recent are shown first. 96 new CWE-294 CVEs have been recorded so far in 2026 (23 in 2025).
- CVE-2025-49752
Azure Bastion Elevation of Privilege Vulnerability
Critical · CVSS 10.0 · EPSS 59th2025-11-20 - CVE-2026-88278
GV-LPCLPC2011/2211 - ONVIF WS-Security PasswordDigest Replay
Critical · CVSS 9.8 · EPSS 40th2026-09-10 - CVE-2026-86219
Authen::SASL::Perl::DIGEST_MD5 versions before 2.2100 for Perl accept replayed authentication responses via unverified nonce in server_step