CVE-2026-21900: Nasa Cryptolib

Medium severity, CVSS 5.9. EPSS: 0.6% chance of exploitation in the next 30 days.

CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight System (cFS) and a ground station. Prior to version 1.4.3, an out-of-bounds heap read vulnerability in cryptography_encrypt() occurs when parsing JSON metadata from KMC server responses. The flawed strtok iteration pattern uses ptr + strlen(ptr) + 1 which reads one byte past allocated buffer boundaries when processing short or malformed metadata strings. This issue has been patched in version 1.4.3.

Affected products

• Nasa Cryptolib: before 1.4.3 (fixed in 1.4.3)

Published 2026-01-10. Last modified 2026-06-17.