CVE-2026-79954

Overview

NASA CryptoLib 1.5.0 has an authentication downgrade issue in its Telecommand receive path. The receiver chooses the Security Association for SDLS processing only from the SPI in the incoming frame, without confirming that the SA is authorized for the frame's GVCID. This matters because it can weaken the intended authentication and authorization boundaries for telecommand processing.

Description

NASA CryptoLib 1.5.0 contains an authentication downgrade vulnerability in the Telecommand (TC) receive path. The receiver selects the Security Association used for SDLS processing solely from the SPI field inside the incoming frame, but it does not verify that the selected SA is authorized for the frame's GVCID.

Impact

The issue primarily affects integrity and authentication, with potential confidentiality and availability consequences if unauthorized or weaker security associations are accepted for telecommand frames. It can allow a frame to be processed under an SA that was not intended for the associated GVCID, undermining expected command authorization controls. Spacecraft, ground systems, and mission operations using NASA CryptoLib 1.5.0 for Telecommand receive are most at risk. Defenders should treat this as a high-priority integrity and access-control weakness in space command and control environments.

Remediation

Apply a vendor patch or update to a fixed NASA CryptoLib release if available. If no patch is available, enforce strict validation that the SPI-selected Security Association is authorized for the frame's GVCID before SDLS processing. Reject or quarantine frames where the SA is not explicitly mapped to the expected GVCID. Maintain an allowlist of valid SPI-to-SA-to-GVCID associations and monitor for unexpected SA selections or rejected frames. Restrict network exposure of Telecommand receive interfaces and apply compensating controls such as additional authentication, integrity checks, and command authorization review.

Risk context

The reported CVSS v3 score is 9.8 critical and CVSS v4 is 8.7, indicating high severity. No EPSS value is provided, so exploitation likelihood cannot be inferred from EPSS. Defenders should prioritize remediation for any exposed Telecommand receive path using NASA CryptoLib 1.5.0, especially where telecommand receive interfaces are reachable from untrusted networks or where SA/GVCID mappings are not tightly controlled.

Affected products

• NASA CryptoLib 1.5.0