CVE-2026-107785

MEDIUMCVSS 6.3/10

Last modified

CVE-2026-107785 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. Crux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires.

Description

Crux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires. The agent does not validate this size; instead it attempts to use the `wg set` command to update the live tunnel, and write the invalid key to the WireGuard configuration file. The update fails, so the live tunnel keeps using its previous preshared key until the tunnel is shut down. The tunnel will fail to start when restarted. For a peer which has never successfully negotiated a 32-byte bilocation key in a Crux C2 organization which has the "Enforce SKA Use" setting turned off, no preshared key will be set for the tunnel. Therefore, an attacker who is able to intercept and store the peer's traffic, and has access (or will have access) to a cryptographically relevant quantum computer, will be able to decrypt the tunnel.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Sirius Computer, Inc.Crux Agent>= 1.9.0, < 2.0.3

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-107785?
Crux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires. The agent does not validate this size; instead it attempts to use the `wg set` command to update the live tunnel, and write the invalid key to the WireGuard configuration file. The update fails, so the live tunnel keeps using its previous preshared key until the tunnel is shut down. The tunnel will fail to start when restarted. For a peer which has never successfully negotiated a 32-byte bilocation key in a Crux C2 organization which has the "Enforce SKA Use" setting turned off, no preshared key will be set for the tunnel. Therefore, an attacker who is able to intercept and store the peer's traffic, and has access (or will have access) to a cryptographically relevant quantum computer, will be able to decrypt the tunnel.
How severe is CVE-2026-107785?
CVE-2026-107785 has a CVSS score of 6.3/10 (MEDIUM severity).
How do I fix CVE-2026-107785?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST