CVE-2025-3110

HIGH

Published Jul 8, 2026 Modified Jul 10, 2026 CWE-444

Description

OpenVPN Access Server 2.7.2 through 3.1.0 accepts bare line-feed sequences inside HTTP header values, allowing remote attackers to perform HTTP request smuggling when deployed behind a reverse proxy

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0026

Probability of exploitation

0.17%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-444 CWE-444

Affected Products

Vendor	Product	Versions
openvpn	openvpn_access_server	2.7.2 — 3.1.0

References

Other References

https://openvpn.net/as-docs/as-3-2-release-notes.html

Frequently Asked Questions

What is CVE-2025-3110? +

OpenVPN Access Server 2.7.2 through 3.1.0 accepts bare line-feed sequences inside HTTP header values, allowing remote attackers to perform HTTP request smuggling when deployed behind a reverse proxy It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-3110? +

CVE-2025-3110 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2025-3110? +

CVE-2025-3110 affects products from openvpn, specifically: openvpn_access_server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-3110? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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