{"id":"CVE-2026-93483","details":"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 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.","modified":"2026-10-16T03:00:34.704273861Z","published":"2026-10-15T03:43:10.406Z","database_specific":{"cwe_ids":["CWE-348"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93483.json","cna_assigner":"mitre"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93483.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93483"},{"type":"ADVISORY","url":"https://www.znuny.org/advisories"},{"type":"ADVISORY","url":"https://www.znuny.org/en/advisories/zsa-2026-14"},{"type":"PACKAGE","url":"https://github.com/znuny/znuny"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/znuny/znuny","events":[{"introduced":"0"},{"fixed":"7c8f705278f9118a4424db5cbc6d4bb3c99134bc"},{"fixed":"29c529b1abd3e3daf89ab4b894bfce3822beef88"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"fixed":"6.5.25"},{"introduced":"7.0.0"},{"fixed":"7.3.7"}]}}],"versions":["rel-7_3_6","rel-6_5_24","rel-6_5_23","rel-7_3_5","rel-6_5_22","rel-7_3_4","rel-6_5_21","rel-7_3_3","rel-6_5_20","rel-7_3_2","rel-7_3_1","rel-6_5_18","rel-7_2_2","rel-6_5_17","rel-6_5_16","rel-7_2_1","rel-6_5_15","rel-7_1_7","rel-6_5_14","rel-7_1_6","rel-7_1_5","rel-6_5_13","rel-6_5_12","rel-7_1_4","rel-6_5_11","rel-7_1_3","rel-7_1_2","rel-6_5_10","rel-7_1_1","rel-6_5_9","rel-6_5_8","rel-7_0_17","rel-6_5_7","rel-7_0_16","rel-6_5_6","rel-7_0_15","rel-7_0_14","rel-6_5_5","rel-7_0_13","rel-7_0_12","rel-6_5_4","rel-7_0_11","rel-7_0_10","rel-7_0_9","rel-7_0_8","rel-7_0_7","rel-7_0_6","rel-6_5_3","rel-7_0_5","rel-6_5_2","rel-7_0_4","rel-7_0_3","rel-7_0_2","rel-7_0_1","rel-6_5_1","rel-6_4_4","rel-6_4_3","rel-6_4_2","rel-6_1_1","rel-6_0_35","rel-6_0_34","rel-6_0_33","rel-6_0_13","rel-6_0_12","rel-6_0_11","rel-6_0_10","rel-6_0_9","rel-6_0_8","rel-6_0_7","rel-6_0_6","rel-6_0_5","rel-6_0_0_rc1","rel-6_0_0_beta5","rel-6_0_0_beta4","rel-6_0_0_beta3","rel-6_0_0_beta2","rel-6_0_0_beta1","rel-6_0_0_alpha1","rel-5_0_0_beta3","rel-5_0_0_beta2","rel-5_0_0_beta1","rel-5_0_0_alpha1","rel-4_0_0_rc1","rel-4_0_0_beta5","rel-4_0_0_beta4","rel-4_0_0_beta3","rel-4_0_0_beta2","rel-4_0_0_beta1","rel-3_3_1","rel-3_3_0_rc1","rel-3_3_0_beta5","rel-3_3_0_beta4","rel-3_3_0_beta3","rel-3_3_0_beta2","rel-3_3_0_beta1","rel-3_2_4","rel-3_2_3","rel-3_2_2","rel-3_2_1","rel-3_2_0_rc1","rel-3_2_0_beta5","rel-3_2_0_beta4","rel-3_2_0_beta3","rel-3_2_0_beta2","rel-3_2_0_beta1","rel-3_1_4","rel-3_1_2","rel-3_1_0_rc1","rel-3_1_0-rc1","rel-3_1_0_beta5","rel-3_1_0-b5","rel-3_1_0_beta4","rel-3_1_0-b4","rel-3_1_0_beta3","rel-3_1_0-b3","rel-3_1_0_beta1","rel-3_1_0-b1","rel-3_0_4","rel-3_0_3","rel-3_0_2","rel-3_0_1","rel-3_0_0_beta7","rel-3_0_0-b7","rel-3_0_0_beta5","rel-3_0_0-b5","rel-3_0_0_beta4","rel-3_0_0-b4","rel-3_0_0_beta3","rel-3_0_0-b3","rel-3_0_0_beta2","rel-3_0_0-b2","rel-2_4_4","rel-2_4_3","rel-2_4_2","rel-2_4_1","rel-2_4_0_beta6","rel-2_4_0-b6","rel-2_4_0_beta4","rel-2_4_0-b4","rel-2_4_0_beta3","rel-2_4_0-b3","rel-2_4_0_beta2","rel-2_4_0-b2","rel-2_3_2","rel-2_3_1","rel-2_2_2","rel-2_2_1","rel-2_2_0_beta4","rel-2_2_0-b4","rel-2_2_0_beta3","rel-2_2_0-b3","rel-2_2_0_beta2","rel-2_2_0-b2","rel-2_2_0_beta1","rel-2_2_0-b1","rel-2_1_3","rel-2_1_2","rel-2_1_1","rel-2_1_0_beta2","rel-2_1_0-b2","rel-2_1_0_beta1","rel-2_1_0-b1","rel-2_0_3","rel-2_0_2","rel-2_0_1","rel-2_0_0_beta1","rel-2_0_0-b1","rel-1_2_1","rel-1_2_0_beta3","rel-1_2_0-b3","rel-1_2_0_beta2","rel-1_2_0-b2","rel-1_2_0_beta1","rel-1_2_0-b1","rel-1_1_0_rc2","rel-1_1_0-RC2","rel-1_1_0_rc1","rel-1_1_0-RC1","rel-1_0_0_rc3","rel-1_0_0-RC3","rel-1_0_0_rc2","rel-1_0_0-RC2","rel-1_0_0_rc1","rel-1_0_0-RC1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93483.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}