Buffer overflow in Nasa Cryptolib
CVE-2026-21897
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, the Crypto_Config_Add_Gvcid_Managed_Parameters function only checks whether gvcid_counter > GVCID_MAN_PARAM_SIZE. As a result, it allows up to the 251st entry, which causes a write past the end of the array, overwriting gvcid_counter located immediately after gvcid_managed_parameters_array[250]. This leads to an out-of-bounds write, and the overwritten gvcid_counter may become an arbitrary value, potentially affecting the parameter lookup/registration logic that relies on it. This issue has been patched in version 1.4.3.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (19.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Nasa Cryptolib — versions < 1.4.3
Weakness classification (CWE)
References
- github.com/nasa/CryptoLib/security/advisories/GHSA-9x7j-gx23-7m5r (Vendor Advisory)
- github.com/nasa/CryptoLib/releases/tag/v1.4.3 (Release Notes)
Frequently asked questions
- What is CVE-2026-21897?
- CVE-2026-21897 is a high-severity vulnerability in Nasa Cryptolib, classified under Out-of-bounds Write. CVSS score: 7.3/10. Published 2026-01-10.
- How severe is CVE-2026-21897?
- High severity. CVSS v3 base score is 7.3 out of 10.