CVE-2026-19538
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 open.
INFO
Published Date :
Aug. 26, 2026, 8:47 a.m.
Last Modified :
Aug. 26, 2026, 8:47 a.m.
Remotely Exploit :
No
Source :
NLnet Labs
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | 206fc3a0-e175-490b-9eaa-a5738056c9f6 |
Solution
- Validate ACLs for proxy protocol port restrictions.
- Update ACL logic to prevent bypasses.
- Test access controls thoroughly.
- Apply configuration changes.
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CVE-2026-19538 vulnerability anywhere in the article.