WireGuard wg(4) Driver MAC Verification Bypass (CVE-2026-58085)
CVE-2026-58085 Published on August 19, 2026

Missing MAC validation in wg(4) packet decryption
After dispatching a decrypt operation to OCF and receiving the result, the wg(4) driver failed to check whether the MAC verification step succeeded. The driver thus silently accepted packets with an invalid Poly1305 authentication tag. A remote attacker who can send UDP packets to a WireGuard endpoint, and who can guess the bounds of the receiver's replay window, can inject forged or modified transport data packets into the tunnel. A remote attacker who can intercept WireGuard packets bound for a FreeBSD host can modify the ciphertext and authenticated data without detection by the receiver.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-58085 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
HIGH
Availability Impact:
NONE

Weakness Type

Improper Verification of Cryptographic Signature

The software does not verify, or incorrectly verifies, the cryptographic signature for data.


Products Associated with CVE-2026-58085

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FreeBSD
 

Affected Versions

FreeBSD: