CVE-2026-21899
CryptoLib has an out-of-bounds read and crash vulnerability when decoding an empty Base64url string
- State
- Published
- Severity
- 4.7 Medium
- Published
- Jan 10, 2026
- Updated
- Jan 12, 2026
- Reserved
- Jan 5, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.7 Medium | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L | GitHub_M |
Weaknesses
- CWE-125 Out-of-bounds Read
Affected Products
| Product | Versions |
|---|---|
CryptoLibnasa |
|
References
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