Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nasa | Cryptolib | < 1.4.3 |
Related Weaknesses (CWE)
References
- https://github.com/nasa/CryptoLib/commit/2372efd3da1ccb226b4297222e25f41ecc84821Patch
- https://github.com/nasa/CryptoLib/releases/tag/v1.4.3Release Notes
- https://github.com/nasa/CryptoLib/security/advisories/GHSA-4g6v-36fv-qcvwExploitVendor Advisory
- https://github.com/nasa/CryptoLib/security/advisories/GHSA-4g6v-36fv-qcvwExploitVendor Advisory
FAQ
What is CVE-2026-21900?
CVE-2026-21900 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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 Syst...
How severe is CVE-2026-21900?
CVE-2026-21900 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-21900?
Check the references section above for vendor advisories and patch information. Affected products include: Nasa Cryptolib.