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, in base64urlDecode, padding-stripping dereferences input[inputLen - 1] before checking that inputLen > 0 or that input != NULL. For inputLen == 0, this becomes an OOB read at input[-1], potentially crashing the process. If input == NULL and inputLen == 0, it dereferences NULL - 1. 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/releases/tag/v1.4.3Release Notes
- https://github.com/nasa/CryptoLib/security/advisories/GHSA-wc29-5hw7-mpj8ExploitVendor Advisory
FAQ
What is CVE-2026-21899?
CVE-2026-21899 is a vulnerability with a CVSS score of 4.7 (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-2026-21899?
CVE-2026-21899 has been rated MEDIUM with a CVSS base score of 4.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-21899?
Check the references section above for vendor advisories and patch information. Affected products include: Nasa Cryptolib.