CVE-2026-56766
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-P…
Public exploit code
Working exploit or proof of concept code has been published for this vulnerability. Treat unpatched systems as at risk.
- Hydra - Stack Buffer Overflow2026-07-07 · remote · linux
Impact
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.
Affected products
| Product | Affected versions |
|---|---|
| Hydra | through 9.7 |
Versions were read from the advisory text. No structured product data has been published for this record yet.