CVE-2026-19538 — Bypass of BLOCKED ACL items on proxy protocol port over TCP or TLS

CVE-2026-19538

Bypass of BLOCKED ACL items on proxy protocol port over TCP or TLS PUBLISHED

Description (CNA)

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 open.

Affected (CNA)

Vendor / product	Versions
NLnet Labs / NSD	affected 4.8.0 before 4.15.1

CWE

CWE-290, CWE-672

References

https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-19538.txt

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.