CVE-2026-56766
Hydra - Stack Buffer Overflow in NTLM Authentication Handler
Vexday Risk Score
21Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 8.6EPSS 0.5%KEV nãoPoC —Nuclei —Metasploit —Patch referenciado
Lifecycle
25 Jun 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
vanhauser-thc · thc-hydraWant to know if your infrastructure is exposed to this?
Talk to TrueHacking →