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CVE-2026-21897

HIGHCVSS 7.3/10EPSS 0.26%

Last modified

CVE-2026-21897 is a high-severity vulnerability rated 7.3/10 on the CVSS scale. 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. EPSS estimates a 0.26% chance of exploitation in the next 30 days.

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_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.

Metrics

CVSS 3.1
7.3/10

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

EPSS Probability
0.26%

17.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
NasaCryptolib< 1.4.3

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is 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.
How severe is CVE-2026-21897?
CVE-2026-21897 has a CVSS score of 7.3/10 (HIGH severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.
How do I fix CVE-2026-21897?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-21897?

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Source: NVD / NIST