CVE-2025-26465
MEDIUMOpenSSH 6.9-9.7 - Machine-in-the-Middle Attack via VerifyHostKeyDNS Error Handling
Title source: llmExploitation Summary
EIP tracks 2 public exploits for CVE-2025-26465. PoCs published by rxerium, dolutech.
AI-analyzed exploit summary This repository provides a Nuclei template for detecting vulnerable OpenSSH client versions (6.8p1 to 9.9p1) affected by CVE-2025-26465, a MitM vulnerability when VerifyHostKeyDNS is enabled. It matches against SSH banner strings to identify at-risk hosts.
Description
A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.
Exploits (2)
This repository provides a Nuclei template for detecting vulnerable OpenSSH client versions (6.8p1 to 9.9p1) affected by CVE-2025-26465, a MitM vulnerability when VerifyHostKeyDNS is enabled. It matches against SSH banner strings to identify at-risk hosts.
This repository provides a mitigation script for OpenSSH vulnerabilities CVE-2025-26465 and CVE-2025-26466, focusing on disabling VerifyHostKeyDNS and adjusting MaxStartups to prevent DoS attacks.
References (26)
Scores
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N