{"id":"CVE-2026-21899","summary":"CryptoLib has an out-of-bounds read and crash vulnerability when decoding an empty Base64url string","details":"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 \u003e 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.","aliases":["GHSA-wc29-5hw7-mpj8"],"modified":"2026-08-12T03:51:14.694058425Z","published":"2026-01-10T00:11:18.877Z","database_specific":{"cwe_ids":["CWE-125"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21899.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/nasa/CryptoLib/releases/tag/v1.4.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21899.json"},{"type":"ADVISORY","url":"https://github.com/nasa/CryptoLib/security/advisories/GHSA-wc29-5hw7-mpj8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21899"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nasa/cryptolib","events":[{"introduced":"0"},{"fixed":"9ffda0ff78e8f74c58db4c181923196870e04c3e"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.4.3"}],"source":["AFFECTED_FIELD","CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:nasa:cryptolib:*:*:*:*:*:*:*:*"}}],"versions":["v1.4.2","v1.4.0","v1.3.3","v1.3.2","v1.3.1","v1.3.0","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.1","v1.1.0","v1.0.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21899.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L"}]}