CVE-2026-19538

UNKNOWN 0.0

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

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-290 CWE-672
Vendor	nlnet labs
Product	nsd
Published	Aug 26, 2026
Last Updated	Aug 26, 2026

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Affected Versions

NLnet Labs / NSD

4.8.0 < 4.15.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

Qifan Zhang from Palo Alto Networks