VulnerabilityAnalyzed
CVE-2026-19538
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.
HIGH 8.2EPSS 0.30%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/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
- EPSS
- 0.30% probability · 23th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-290, CWE-672
- Affected
- nlnetlabs/nsd
- Source
- sep@nlnetlabs.nl
References
- https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-19538.txtVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.