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.
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History
Thu, 25 Jun 2026 19:30:00 +0000
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Thu, 25 Jun 2026 18:30:00 +0000
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| 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. | |
| Title | Hydra - Stack Buffer Overflow in NTLM Authentication Handler | |
| Weaknesses | CWE-121 | |
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cvssV3_1
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Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-06-25T18:34:53.467Z
Reserved: 2026-06-22T21:55:17.942Z
Link: CVE-2026-56766
Updated: 2026-06-25T18:34:29.403Z
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OpenCVE Enrichment
Updated: 2026-06-25T19:30:15Z