What is CVE-2026-55199?

CVE-2026-55199 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler

Which CVE IDs does CVE-2026-55199 cover?

CVE-2026-55199 covers the following CVE IDs: CVE-2026-55199. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-55199?

CVE-2026-55199 has a CVSS v3 base score of 5.9, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-55199?

CVE-2026-55199 affects 4 products, including: azl3 libssh 0.10.6-8 on Azure Linux 3.0; azl3 libssh2 1.11.1-2 on Azure Linux 3.0; azl3 libssh2 1.11.1-3 on Azure Linux 3.0; azl3 libssh2 1.11.1-4 on Azure Linux 3.0.

CVE-2026-55199HighCVSS 5.9

libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler

Vendor

Microsoft Security Response Center (MSRC)

Published

June 30, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-55199 →

🎯 Affected products4

azl3 libssh 0.10.6-8 on Azure Linux 3.0
azl3 libssh2 1.11.1-2 on Azure Linux 3.0
azl3 libssh2 1.11.1-3 on Azure Linux 3.0
azl3 libssh2 1.11.1-4 on Azure Linux 3.0

✅ Remediation

KBCBL-Mariner Releases (Security Update) — fixed build 1.11.1-4

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55199
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade