{"id":78954,"date":"2026-05-28T09:46:29","date_gmt":"2026-05-28T06:16:29","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2026-9803-keycloak-keycloak-denial-of-service-via-malformed-authorization-header\/"},"modified":"2026-05-28T09:46:29","modified_gmt":"2026-05-28T06:16:29","slug":"cve-2026-9803-keycloak-keycloak-denial-of-service-via-malformed-authorization-header","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2026-9803-keycloak-keycloak-denial-of-service-via-malformed-authorization-header\/","title":{"rendered":"CVE-2026-9803 &#8211; Keycloak: keycloak: denial of service via malformed authorization header"},"content":{"rendered":"<p>CVE ID :CVE-2026-9803<\/p>\n<p>  Published : May 28, 2026, 6:16 a.m. | 15\u00a0minutes ago<\/p>\n<p>  Description :A flaw was found in Keycloak&#8217;s ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed &#8216;Authorization: Bearer&#8217; header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.<\/p>\n<p>  Severity: 5.3 | MEDIUM<\/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-2026-9803 Published : May 28, 2026, 6:16 a.m. | 15\u00a0minutes ago Description :A flaw was found in Keycloak&#8217;s ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed &#8216;Authorization: Bearer&#8217; header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing &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-78954","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/78954","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=78954"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/78954\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=78954"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=78954"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=78954"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}