CVE-2026-56766
HIGHHydra - Stack Buffer Overflow in NTLM Authentication Handler
Title source: cnaExploitation Summary
EIP tracks 1 public exploit for CVE-2026-56766. PoCs published by banyamer.
AI-analyzed exploit summary This exploit demonstrates a stack buffer overflow in Hydra <= 9.7 by sending a malicious NTLM Type-2 challenge with an excessively long domain name field, triggering a SIGSEGV in the NTLM authentication handler for SMTP/POP3/IMAP modules.
Description
Hydra through 9.7, fixed in commit 9cc84c2, contains a stack buffer overflow in NTLM authentication across SMTP, POP3, IMAP, NNTP, HTTP, HTTP-Proxy, and HTTP-Proxy-Urlenum modules when processing malicious NTLM Type-2 challenges. A malicious server can send a crafted NTLM Type-2 challenge with an excessively long domain string, causing base64-encoded response data to overflow a 500-byte stack buffer by 18 to 330 bytes, enabling remote code execution on systems without stack protection.
Exploits (1)
This exploit demonstrates a stack buffer overflow in Hydra <= 9.7 by sending a malicious NTLM Type-2 challenge with an excessively long domain name field, triggering a SIGSEGV in the NTLM authentication handler for SMTP/POP3/IMAP modules.
References (2)
Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H