CVE-2025-12106CWE-126

CVE-2025-12106

Critical · published December 1, 2025

CVSS v3.1
9.1
EPSS
1%
Percentile
45.7
In the wild
Unconfirmed
What it is

🔥 A crafty attacker needs only a malformed IP address to pull off a heap buffer over-read in OpenVPN 2.7_alpha1 through 2.7_rc1! Think of it like a diner who slipped a fake food order into the kitchen — the chefs start preparing the wrong dish based on the misleading request, causing chaos in meal delivery and possibly ruining the evening. This weakness could lead to sensitive data being exposed or even system crashes, as the server struggles to handle the unexpected input. An attacker could exploit this vulnerability to gain unauthorized insights or disrupt services, leaving your network vulnerable and in disarray!

Put simply

Think of it like a diner who slipped a fake food order into the kitchen — the chefs start preparing the wrong dish based on the misleading request, causing chaos in meal delivery and possibly ruining the evening. Insufficient argument validation in OpenVPN allows attackers to trigger a heap buffer over-read while parsing IP addresses, potentially leading to memory corruption or information exposure.

What to do

This weakness could lead to sensitive data being exposed or even system crashes, as the server struggles to handle the unexpected input. An attacker could exploit this vulnerability to gain unauthorized insights or disrupt services, leaving your network vulnerable and in disarray! Immediately upgrade to the latest stable version of OpenVPN that patches this vulnerability. Implement input validation measures to ensure IP addresses are correctly formatted and sanitized to prevent such exploits. Regularly audit your systems for vulnerabilities to stay one step ahead! You've got this! With a quick update and some vigilance, your systems will be fortified against this threat! 🛡️

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00556 · 45.7th percentile
Weakness
CWE-126 · Buffer Over-read
Published
2025-12-01T18:16Z
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/openvpnall versions—
References (2)
EPSS history
Timeline
  • 01 DEC 12:43Z
    Insufficient argument validation in OpenVPN 2.7_alpha1 through 2.7_rc1 allows an attacker to trigger a heap buffer over-read when parsing IP addresses
    cvelistv5