CVE-2026-55199
Multiple security vulnerabilities were discovered in libssh2, a client-side C library implementing the SSH2 protocol which could result in memory disclosure, denial of service or potentially the execution of arbitrary code. https://security-tracker.debian.org/tracker/DSA-6365-1
CSIRTS triage
- What
- Multiple security vulnerabilities could result in memory disclosure, denial of service, or potentially the execution of arbitrary code.
- Who is affected
- Deployments of libssh2 are affected.
- Urgency
- Remediation is urgent due to the potential for arbitrary code execution.
- Action
- Update to the latest version of libssh2.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.41% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 33% of all EPSS-scored CVEs.
Advisory coverage (5)
- unknownMultiple vulnerabilities in Microsoft Azure Linux (July 7, 2026)cert-fr-avis · 2026-07-07
- high[UPDATE] [high] libssh2: Multiple vulnerabilitiescert-bund · 2026-07-03
- unknownDSA-6365-1 libssh2 - security updatedebian · 2026-06-25
- unknownNCSC-2026-0210 [1.01] [M/H] Vulnerabilities fixed in libssh2 by libsshncsc-nl · 2026-06-24
- mediumCVE-2026-55199: libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handlermsrc · 2026-06-09
External references
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