After dispatching a decrypt operation to OCF and receiving the result, the wg(4) driver failed to check whether the MAC verification step succeeded. (CVE-2026-58085)
The wg(4) driver in FreeBSD fails to verify the success of the MAC (Poly1305) authentication step after decrypting packets. This flaw allows remote attackers who can send UDP packets to a WireGuard endpoint and guess the replay window bounds to inject forged or modified transport data packets into the tunnel. Additionally, attackers intercepting WireGuard packets can modify ciphertext and authenticated data without detection.
AI Analysis
Technical Summary
CVE-2026-58085 describes a vulnerability in the FreeBSD wg(4) driver where, after dispatching a decrypt operation to the Open Crypto Framework (OCF) and receiving the result, the driver does not check whether the Poly1305 MAC verification succeeded. This omission causes the driver to silently accept packets with invalid authentication tags. Consequently, a remote attacker capable of sending UDP packets to a WireGuard endpoint and guessing the receiver's replay window bounds can inject forged or modified packets. Furthermore, an attacker intercepting WireGuard packets destined for a FreeBSD host can alter ciphertext and authenticated data without detection by the receiver.
Potential Impact
The vulnerability allows remote attackers to inject forged or modified packets into a WireGuard VPN tunnel on FreeBSD systems, bypassing authentication checks. This undermines the integrity and authenticity guarantees of the WireGuard protocol on affected hosts, potentially enabling data tampering or injection attacks within the VPN tunnel.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider restricting UDP access to WireGuard endpoints to trusted sources and monitor for unusual activity. Avoid relying on the affected FreeBSD wg(4) driver for critical security until patched.
After dispatching a decrypt operation to OCF and receiving the result, the wg(4) driver failed to check whether the MAC verification step succeeded. (CVE-2026-58085)
Description
The wg(4) driver in FreeBSD fails to verify the success of the MAC (Poly1305) authentication step after decrypting packets. This flaw allows remote attackers who can send UDP packets to a WireGuard endpoint and guess the replay window bounds to inject forged or modified transport data packets into the tunnel. Additionally, attackers intercepting WireGuard packets can modify ciphertext and authenticated data without detection.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-58085 describes a vulnerability in the FreeBSD wg(4) driver where, after dispatching a decrypt operation to the Open Crypto Framework (OCF) and receiving the result, the driver does not check whether the Poly1305 MAC verification succeeded. This omission causes the driver to silently accept packets with invalid authentication tags. Consequently, a remote attacker capable of sending UDP packets to a WireGuard endpoint and guessing the receiver's replay window bounds can inject forged or modified packets. Furthermore, an attacker intercepting WireGuard packets destined for a FreeBSD host can alter ciphertext and authenticated data without detection by the receiver.
Potential Impact
The vulnerability allows remote attackers to inject forged or modified packets into a WireGuard VPN tunnel on FreeBSD systems, bypassing authentication checks. This undermines the integrity and authenticity guarantees of the WireGuard protocol on affected hosts, potentially enabling data tampering or injection attacks within the VPN tunnel.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider restricting UDP access to WireGuard endpoints to trusted sources and monitor for unusual activity. Avoid relying on the affected FreeBSD wg(4) driver for critical security until patched.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-ph3x-qgrx-fv78
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-58085"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a85b4a3acd9273b49250770
Added to database: 08/19/2026, 13:50:27 UTC
Last enriched: 08/19/2026, 13:57:55 UTC
Last updated: 08/19/2026, 13:57:55 UTC
Views: 2
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