---
cve: "CVE-2026-21900"
severity: "HIGH"
cvss: 8.2
epss: "52%"
vendor: "NASA"
kev: false
exploited: false
published: "2026-01-10 01:16:18"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-03T04:54:52+02:00"
---

# CVE-2026-21900

> 8.2 HIGH · 🧪 PoC

## Beschreibung

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-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 9ffda0ff78e8f74c58db4c181923196870e04c3e (Commit)
- 2372efd3da1ccb226b4297222e25f41ecc84821d (Commit)

## Referenzen

- <https://github.com/nasa/CryptoLib/security/advisories/GHSA-4g6v-36fv-qcvw>
- <https://github.com/nasa/CryptoLib/commit/2372efd3da1ccb226b4297222e25f41ecc84821d>
- <https://github.com/nasa/CryptoLib/releases/tag/v1.4.3>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-21900) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_