CVE-2026-107785 (GCVE-0-2026-107785)

Vulnerability from cvelistv5 – Published: 2026-10-09 13:15 – Updated: 2026-10-09 16:46
VLAI
Title
Crux Agent silently fails SKA preshared key rotation when SHA-512 peering is negotiated
Summary
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.
Severity
6.3 (Medium)
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:U/S:N/AU:Y/R:A/V:C/RE:L/U:Amber
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-09 16:15 UTC
CWE
  • CWE-394 - Unexpected Status Code or Return Value
  • CWE-252 - Unchecked Return Value
  • CWE-325 - Missing Cryptographic Step
Assigner
sirius CNA under the mitre root
CNA scorecard – unranked: 1 record in the last 180 days, 10 needed details
References
Impacted products
Vendor Product Version CPE status
Sirius Computer, Inc. Crux Agent Affected: 1.9.0 , < 2.0.3 (semver)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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