{"id":"CVE-2026-93483","title":"In Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header","summary":"In Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header. Because the application incorrectly trusts this …","severity":"critical","cwe":["CWE-348"],"published":"2026-10-15","updated":"2026-10-15","sourceUpdated":"2026-10-15T04:18:30.153","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93483","references":[{"url":"https://www.znuny.org/advisories","label":"cve@mitre.org"},{"url":"https://www.znuny.org/en/advisories/zsa-2026-14","label":"cve@mitre.org"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-15T04:46:37.142Z","vendor":"Znuny","product":"Znuny","affected":["Znuny < 6.5.25","Znuny >= 7.0.0 < 7.3.7"],"cvss":9.5,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/AU:Y/R:U/RE:L/U:Red","cvssSource":"cna","slug":"CVE-2026-93483","body":"## Overview\n\nIn Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header. Because the application incorrectly trusts this header, an attacker can impersonate any user, including administrators, without requiring a password. This grants full access to confidential data and system controls. More specifically, the HTTPBasicAuth modules for the agent (Kernel::System::Auth::HTTPBasicAuth) and customer (Kernel::System::CustomerAuth::HTTPBasicAuth) interfaces read the username to log in not only from $ENV{REMOTE_USER} (set by the web server after successful authentication), but also, as a fallback, from $ENV{HTTP_REMOTE_USER}, which is populated directly from an attacker-controllable \"Remote-User\" request header. On systems where HTTPBasicAuth was configured as the authentication backend, this allowed an attacker to log in as any existing user by sending a request with a forged Remote-User header, without providing any credentials.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":52,"depthScoreParts":{"impact":52.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":222039,"id":"CVE-2026-93483","ts":1792043621307,"field":"cvss","old":null,"new":"9.5"},{"seq":222038,"id":"CVE-2026-93483","ts":1792043621307,"field":"severity","old":"none","new":"critical"}]}