{"id":"CVE-2026-16434","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-16434","generatedAt":"2026-10-28T09:41:45.207Z","title":"Adminer 4.6.0 through 5.5.0 (fixed in 5.5.1) contains an incomplete fix for a prior X-Forwarded-Prefix vulnerability (GHSA-8478-xrj3-h9c2).","description":"Adminer 4.6.0 through 5.5.0 (fixed in 5.5.1) contains an incomplete fix for a prior X-Forwarded-Prefix vulnerability (GHSA-8478-xrj3-h9c2). The validation guard (bootstrap.inc.php) only rejects prefixes matching ^/[^/], blocking //evil.com but allowing values such as /\\evil.com whose second character is a backslash. Because browsers normalize backslash to forward slash, a network-path reference survives into REQUEST_URI and reaches cookie_path(), affecting the Set-Cookie Path attribute. Exploitation requires that clients can set the X-Forwarded-Prefix header (a misconfigured or absent reverse proxy). Impact is limited to anomalous cookie-path scoping.","published":"2026-08-25T02:16:40.000Z","lastModified":"2026-10-12T15:10:00.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":2.3,"severity":"LOW","vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-20"],"affected":[],"epss":{"score":0.00389,"percentile":0.32854,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.39%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/vrana/adminer/security/advisories/GHSA-fr74-9mf9-gf44","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/adminer-before-x-forwarded-prefix-backslash-bypass","source":"disclosure@vulncheck.com"},{"url":"https://github.com/vrana/adminer/security/advisories/GHSA-fr74-9mf9-gf44","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-16434","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}