CVE-2026-21900: CryptoLib Has Out-of-Bounds Read in KMC Encrypt Metadata Parsing via Flawed strtok Pattern
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 cryptographyencrypt() 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 Software
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Event History
Frequently Asked Questions
What is the severity of CVE-2026-21900?
CVE-2026-21900 has been classified as a moderate severity vulnerability due to its potential to cause an out-of-bounds heap read.
How do I fix CVE-2026-21900?
To fix CVE-2026-21900, upgrade CryptoLib to version 1.4.3 or later.
What versions of CryptoLib are affected by CVE-2026-21900?
CVE-2026-21900 affects all versions of CryptoLib prior to version 1.4.3.
What type of vulnerability is CVE-2026-21900?
CVE-2026-21900 is categorized as a heap-related vulnerability that involves an out-of-bounds read.
What is the potential impact of CVE-2026-21900?
The potential impact of CVE-2026-21900 includes unauthorized access to sensitive data and possible denial of service.