CVE-2026-21900
Prior to version 1.4.3, an out-of-bounds heap read vulnerability in cryptography_encrypt() occurs when parsing JSON metadata from KMC server responses.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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, an out-of-bounds heap read vulnerability in cryptography_encrypt() 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.
- CVSS 4.0
- 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.58% probability · 46th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- nasa/cryptolib
- Source
- security-advisories@github.com
References
- https://github.com/nasa/CryptoLib/commit/2372efd3da1ccb226b4297222e25f41ecc84821dPatch
- https://github.com/nasa/CryptoLib/releases/tag/v1.4.3Release Notes
- https://github.com/nasa/CryptoLib/security/advisories/GHSA-4g6v-36fv-qcvwExploit, Vendor Advisory
- https://github.com/nasa/CryptoLib/security/advisories/GHSA-4g6v-36fv-qcvwExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.