{"id":80702,"date":"2026-06-17T22:14:18","date_gmt":"2026-06-17T18:44:18","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2026-55199-libssh2-pre-authentication-dos-via-ssh_msg_ext_info-handler\/"},"modified":"2026-06-17T22:14:18","modified_gmt":"2026-06-17T18:44:18","slug":"cve-2026-55199-libssh2-pre-authentication-dos-via-ssh_msg_ext_info-handler","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2026-55199-libssh2-pre-authentication-dos-via-ssh_msg_ext_info-handler\/","title":{"rendered":"CVE-2026-55199 &#8211; libssh2 &#8211; Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler"},"content":{"rendered":"<p>CVE ID :CVE-2026-55199<\/p>\n<p>  Published : June 17, 2026, 6:44 p.m. | 58\u00a0minutes ago<\/p>\n<p>  Description :libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src\/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not apply to CPU-bound loops.<\/p>\n<p>  Severity: 8.2 | HIGH<\/p>\n<p>  Visit the link for more details, such as CVSS details, affected products, timeline, and more&#8230;\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CVE ID :CVE-2026-55199 Published : June 17, 2026, 6:44 p.m. | 58\u00a0minutes ago Description :libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src\/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-80702","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/80702","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=80702"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/80702\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=80702"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=80702"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=80702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}