Is CVE-2026-21898 in the CISA KEV catalog?

No. CVE-2026-21898 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-21898?

CVE-2026-21898 has a CVSS v3 base score of 8.2 (HIGH).

What is the EPSS score for CVE-2026-21898?

CVE-2026-21898 has an EPSS score of 0.41% (33th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-21898

HIGH

8.2

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, the Crypto_AOS_ProcessSecurity function reads memory without valid bounds checking when parsing AOS frame hashes. This issue has been patched in version 1.4.3.

CWE-125Out-of-bounds Read

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

0.41%probability of exploitation in 30 days

33rdpercentile

Low risk: more likely to be exploited than 33% of all known CVEs.

References

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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 2026-01-15.