CVE•Published 2026-06-25•Modified 2026-07-14•1 article on news•4 live references•NVD data
CVE-2026-56766
Vulnerability data via NVD (ingested)
CVSS v3.1
8.8
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS percentile
68
Exploit Prediction Scoring System · top 32% of all CVEs
Weaknesses (CWE)
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.
Timeline
Published 2026-06-25
Modified 2026-07-14
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
More intel sources (5)
Shodan report
vuln:CVE-2026-56766Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-56766Censys host search filtered to this CVE id.
grep.app
CVE-2026-56766Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-56766GitHub code search for direct mentions.
Google dork
"CVE-2026-56766" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-56766 on GitHub.