CVE-2025-13086CWE-940

CVE-2025-13086

High · published December 4, 2025

CVSS v3.1
7.5
EPSS
1%
Percentile
50.1
In the wild
Unconfirmed
What it is

⚠️ An attacker could hijack an OpenVPN session just by masquerading as a trusted IP! This improper validation lets them open a session from a different source — talk about identity theft! 🔒 Think of it like someone sneaking into a members-only club by wearing a badge they didn’t earn — they get access while the real member is left out in the cold. That’s what’s happening with OpenVPN sessions when source IPs aren’t properly checked! This vulnerability could lead to a denial of service for legitimate clients, effectively locking them out while the imposter has a grand time inside. If an attacker exploits this, your network’s integrity is at stake, causing potential disruptions and downtime for users who genuinely belong!

Put simply

Think of it like someone sneaking into a members-only club by wearing a badge they didn’t earn — they get access while the real member is left out in the cold. That’s what’s happening with OpenVPN sessions when source IPs aren’t properly checked! The flaw in OpenVPN versions 2.6.0 to 2.6.15 and 2.7_alpha1 to 2.7_rc1 lies in the improper validation of source IP addresses. This oversight allows unauthorized sessions to be created by attackers, resulting in denial of service for legitimate users.

What to do

This vulnerability could lead to a denial of service for legitimate clients, effectively locking them out while the imposter has a grand time inside. If an attacker exploits this, your network’s integrity is at stake, causing potential disruptions and downtime for users who genuinely belong! To defend against this, immediately upgrade OpenVPN to version 2.6.16 or later. Make sure to validate source IP addresses carefully to ensure only legitimate users can open sessions. Regularly review your network security policies to strengthen your defenses! You’ve got this! With these steps, you can secure your OpenVPN setup and keep those pesky imposters out! 🛡️

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00641 · 50.1th percentile
Weakness
CWE-940 · Improper Verification of Source of a Communication Channel
Published
2025-12-04T01:16Z
Affected products (8)
ProductVersionsFixed in
openvpn/openvpnall versions—
openvpn/openvpnall versions—
openvpn/openvpnall versions—
openvpn/openvpnall versions—
openvpn/openvpnall versions—
openvpn/openvpnall versions—
openvpn/openvpnall versions—
openvpn/openvpn≥ 2.6.0, < 2.6.162.6.16
References (3)
EPSS history
Timeline
  • 03 DEC 19:54Z
    Improper validation of source IP addresses in OpenVPN version 2.6.0 through 2.6.15 and 2.7_alpha1 through 2.7_rc1 allows an attacker to open a session from a…
    cvelistv5