CVE-2026-21897 | CryptoLib Has Out-of-Bounds Write in Crypto_Config_Add_Gvcid_Managed_Parameters

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.

Published: 2026-01-10 Last update: 2026-01-15 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-21897 is rated Low Risk (30.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-21897

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-18 0.05% 0.02% -0.03%
2 2026-01-16 0.04% 0.05% +0.01%
3 2026-01-10 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21897

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 3.4 [email protected]

Weakness enumeration for CVE-2026-21897

Affected software / configurations for CVE-2026-21897

Vendor Product Version Raw CPE
nasa cryptolib < 1.4.3 cpe:2.3:a:nasa:cryptolib:*:*:*:*:*:*:*:*

References for CVE-2026-21897

cvelogic Threat Intelligence