NASA CryptoLib up to 1.4.2 Link Security Protocol out-of-bounds

Summaryinfo

A vulnerability was found in NASA CryptoLib up to 1.4.2 and classified as critical. Impacted is an unknown function of the component Link Security Protocol. Such manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2026-21899. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in NASA CryptoLib up to 1.4.2. Affected by this issue is an unknown code of the component Link Security Protocol. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-21899 since 01/05/2026. The exploitation is known to be easy. The attack may be launched remotely. The exploitation requires an enhanced level of successful authentication. There are neither technical details nor an exploit publicly available.

Upgrading to version 1.4.3 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-1895). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• NASA

Name

• CryptoLib

Version

• 1.4.0
• 1.4.1
• 1.4.2

Website

• Product: https://github.com/nasa/CryptoLib/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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