CVE & CISA-KEV Catalog

CVE-2026-21900

MEDIUM
5.9
CVSS v3
NVD

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.

How to fix

Remediation Available
cryptolibNVD
Affected:< 1.4.3Fixed in:1.4.3CVE-2026-21900derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityNone
IntegrityNone
AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.51%probability of exploitation in 30 days
40thpercentile

Moderate risk: more likely to be exploited than 40% of all known CVEs.

References

Exploit1
Release Notes1

Related Vulnerabilities

Other CWE-125 (Out-of-bounds Read) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2014-0160High7.5100%KEVFix
CVE-2025-5777High7.5100%KEV + RansomFix
CVE-2021-4034High7.895%KEVFix
CVE-2023-21769High7.592%-Fix
CVE-2023-49285High8.689%-Fix
CVE-2020-8794Critical9.889%-Fix
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Markdown

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HTML

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-01-16.