How severe is CVE-2025-3110?

CVE-2025-3110 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2025-3110 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-3110?

CVE-2025-3110 affects Openvpn Openvpn Access Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-3110?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2025-3110 published?

CVE-2025-3110 was published on 2026-07-08 and last updated on 2026-07-10.

CVE-2025-3110

CVE-2025-3110 is a high-severity vulnerability in Openvpn Openvpn Access Server with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-444.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.9
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-444
Affected product: Openvpn Openvpn Access Server
Published: 2026-07-08
Last modified: 2026-07-10

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

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
How severe is CVE-2025-3110?: CVE-2025-3110 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2025-3110 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-3110?: CVE-2025-3110 affects Openvpn Openvpn Access Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-3110?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2025-3110 published?: CVE-2025-3110 was published on 2026-07-08 and last updated on 2026-07-10.

References

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

Affected products (1)

cpe:2.3:a:openvpn:openvpn_access_server:*:*:*:*:*:*:*:*

More vulnerabilities in Openvpn Openvpn Access Server

CVE-2023-46850 — Critical (CVSS 9.8): Use after free in OpenVPN version 2.6.0 to 2.6.6 may lead to undefined behavoir, leaking memory buffers or remote…
CVE-2020-8953 — Critical (CVSS 9.8): OpenVPN Access Server 2.8.x before 2.8.1 allows LDAP authentication bypass (except when a user is enrolled in…
CVE-2006-1629 — Critical (CVSS 9.0): OpenVPN 2.0 through 2.0.5 allows remote malicious servers to execute arbitrary code on the client by using setenv with…
CVE-2023-46849 — High (CVSS 7.5): Using the --fragment option in certain configuration setups OpenVPN version 2.6.0 to 2.6.6 allows an attacker to…
CVE-2021-4234 — High (CVSS 7.5): OpenVPN Access Server 2.10 and prior versions are susceptible to resending multiple packets in a response to a reset…
CVE-2022-33738 — High (CVSS 7.5): OpenVPN Access Server before 2.11 uses a weak random generator used to create user session token for the web portal

All CVEs affecting Openvpn Openvpn Access Server →

Other CWE-444 (HTTP Request/Response Smuggling) vulnerabilities

CVE-2026-58150 — Critical (CVSS 10.0): Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling. This…
CVE-2026-57834 — Critical (CVSS 10.0): Apache Traffic Server allows request smuggling if chunked messages are malformed. This issue affects Apache Traffic…
CVE-2025-1867 — Critical (CVSS 10.0): Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in ithewei libhv allows…
CVE-2022-22536 — Critical (CVSS 10.0): SAP NetWeaver Application Server ABAP, SAP NetWeaver Application Server Java, ABAP Platform, SAP Content Server 7.53…
CVE-2018-3907 — Critical (CVSS 10.0): An exploitable vulnerability exists in the REST parser of video-core's HTTP server of the Samsung SmartThings Hub…
CVE-2025-55315 — Critical (CVSS 9.9): Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized…

Browse all CWE-444 (HTTP Request/Response Smuggling) vulnerabilities →