Bug 2493128 (CVE-2026-56766) - CVE-2026-56766 hydra: Hydra: Remote Code Execution via NTLM Authentication Stack Buffer Overflow
Summary: CVE-2026-56766 hydra: Hydra: Remote Code Execution via NTLM Authentication St...
Keywords:
Status: NEW
Alias: CVE-2026-56766
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
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Depends On: 2494115 2494119
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-25 19:04 UTC by OSIDB Bzimport
Modified: 2026-06-29 09:15 UTC (History)
0 users

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Description OSIDB Bzimport 2026-06-25 19:04:00 UTC 
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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