CVE-2026-21900: nasa CryptoLib · Out-of-bounds Read
Affects nasa CryptoLibSource CVE Database V5
Not known to be exploited · CVSS 8.2 High : upgrade to 1.4.3 soon.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.4.3
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade CryptoLib and nasa/CryptoLib to 1.4.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| nasaCryptoLib | Affected
| Fixed in
|
GitHubnasa/CryptoLibpkg:github/nasa/CryptoLibOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
The primary mitigation is to upgrade CryptoLib to version 1.4.3 or later, where the out-of-bounds read issue has been patched. Organizations should conduct a thorough inventory to identify all systems using CryptoLib, especially those involved in spacecraft communication or ground station operations. Beyond upgrading, it is advisable to audit all JSON parsing routines within the software stack for similar unsafe string handling patterns, particularly those using strtok or manual pointer arithmetic. Implementing bounds checking and safer string handling functions can prevent similar vulnerabilities. Network-level protections such as strict filtering of KMC server responses and anomaly detection for malformed metadata can reduce exposure. Additionally, organizations should monitor for any emerging exploit attempts or related threat intelligence. Regular security assessments and code reviews focusing on memory safety in critical communication components are recommended to prevent recurrence.
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.