{"id":"CVE-2026-19538","aliases":["DEBIAN-CVE-2026-19538","EUVD-2026-66376","GHSA-q27j-h4qm-x5f7","UBUNTU-CVE-2026-19538"],"status":"published","title":"Bypass of BLOCKED ACL items on proxy protocol port over TCP or TLS","description":"The BLOCKED access control list items that are evaluated to deny access on the the proxy protocol port can be bypassed completely when connecting over TCP or TLS and sending the query twice on connection that is kept 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labs","product":"nsd"},{"vendor":"nlnetlabs","product":"nsd"}],"references":[{"url":"https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-19538.txt","tags":["vendor-advisory","Vendor Advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19538"},{"url":"https://github.com/advisories/GHSA-q27j-h4qm-x5f7"},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-19538","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-19538","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-19538","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-19538","title":"Bypass of BLOCKED ACL items on proxy protocol port over TCP or TLS","description":"The BLOCKED access control list items that are evaluated to deny access on the the proxy protocol port can be bypassed completely when connecting over TCP or TLS and sending the query twice on connection that is kept 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