CVE-2026-19538Disclosure(nlnetlabs / nsd)

LOWCVSS 7.5 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD 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.

nlnetlabs CVEs Back to dashboard

0.0/ 10 priority

Sources & remediation

Vendor / third-party advisories

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

Weakness type (CWE)

CWE-290CWE-672

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

Threat summary

4 mentions across 3 observed days
Momentum state: stable

What's happening

Technical details provided in 2 signals
Disclosure: 3 classified signals
General: 1 classified signal
Peaked 2d ago at 2 mentions (2026-08-26); latest day: 1
4 total mentions across 3 days

Affected systems

Vendors

nlnetlabs

Products

nsd

Deep dive

Activity timeline4 mentions / 3d

Signal classification2 categories

Disclosure

375.0%

General

125.0%

Referenced assets3 URLs

By indicator

Classification over time

Date	Total	Labels

2026-08-26	2	Disclosure2
2026-08-27	1	Disclosure1
2026-08-30	1	General1

Full discourse4 posts

日本レジストリサービス（JPRS）@JPRS_official45d
Disclosure
【注意喚起】NSDの脆弱性情報が公開されました（CVE-2026-18664、CVE-2026-18916、CVE-2026-19401、CVE-2026-19538） https://jprs.jp/tech/security/2026-08-27-nsd.html
Post summary
JPRS has published vulnerability information for multiple CVEs related to NSD, but the notice contains no technical details, PoC, or exploitation evidence.
01130853
1.3K followersView on X
CVE@CVEnew46d
Disclosure
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 … https://www.cve.org/CVERecord?id=CVE-2026-19538
Post summary
The article discloses CVE‑2026‑19538, noting that ACL blocks on the proxy protocol port can be bypassed via TCP/TLS connections.
000201.2K
58.1K followersView on X
珈琲好き@likecoffee42d
General
NSDの脆弱性情報が公開されました（CVE-2026-18664、CVE-2026-18916、CVE-2026-19401、CVE-2026-19538） https://jprs.jp/tech/security/2026-08-27-nsd.html #%E6%8A%80%E8%A1%93%E7%B3%BB-%E8%B3%87%E6%96%99 #feedly
Post summary
NSD vulnerability information for CVE-2026-18664, CVE-2026-18916, CVE-2026-19401, and CVE-2026-19538 has been published, but no PoC, exploit, patch, or technical details are provided in this text.
0000059
1.5K followersView on X
Infoflowcloud@infoflowcloud46d
Disclosure
🚨*CVE* 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 … https://www.cve.org/CVERecord?id=CVE-2026-19538 ----- Traducción: CVE-2026-19538 Los… https://infoflow.cloud`
Post summary
The post announces CVE-2026-19538 and highlights that access‑control list items on the proxy protocol port can be bypassed over TCP/TLS, but offers no proof‑of‑concept, exploit tool, or mitigation information.
0000027
102 followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	nlnetlabs	nsd	-	-	-

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What researchers are saying

CVE-2026-19538

珈琲好き[verified]@likecoffeeGeneral

NSD vulnerability information for CVE-2026-18664, CVE-2026-18916, CVE-2026-19401, and CVE-2026-19538 has been published, but no PoC, exploit, patch, or technical details are provided in this text.

日本レジストリサービス（JPRS）@JPRS_officialDisclosure

JPRS has published vulnerability information for multiple CVEs related to NSD, but the notice contains no technical details, PoC, or exploitation evidence.

CVE@CVEnewDisclosure

The article discloses CVE‑2026‑19538, noting that ACL blocks on the proxy protocol port can be bypassed via TCP/TLS connections.

Infoflowcloud@infoflowcloudDisclosure

The post announces CVE-2026-19538 and highlights that access‑control list items on the proxy protocol port can be bypassed over TCP/TLS, but offers no proof‑of‑concept, exploit tool, or mitigation information.