Out-of-bounds Read Affecting libssh2 package, versions [0,]
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CONAN-LIBSSH2-21248783
- published19 Oct 2026
- disclosed24 Jul 2026
- creditUnknown
Introduced: 24 Jul 2026
CVE-2026-66034 (opens in a new tab)How to fix?
A fix was pushed into the master branch but not yet published.
Overview
Affected versions of this package are vulnerable to Out-of-bounds Read via the publickey subsystem. An attacker can cause heap memory to be read out-of-bounds by enticing a user to connect to a malicious SSH server, potentially leaking heap pointers that may assist in bypassing memory protections, and may result in denial of service or arbitrary code execution.
Workaround
This vulnerability can be mitigated by strictly avoiding connections to untrusted SSH servers, enforcing outbound network firewall policies to block unknown IP addresses, and utilizing OS-level memory protections and service sandboxing for defense-in-depth.