NASA CryptoLib up to 1.4.2 Link Security Protocol cryptography_encrypt out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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6.5$0-$5k0.00

Summaryinfo

A vulnerability was found in NASA CryptoLib up to 1.4.2. It has been classified as critical. The affected element is the function cryptography_encrypt of the component Link Security Protocol. Performing a manipulation results in out-of-bounds. This vulnerability is identified as CVE-2026-21900. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, was found in NASA CryptoLib up to 1.4.2. This affects the function cryptography_encrypt of the component Link Security Protocol. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-21900 since 01/05/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

Upgrading to version 1.4.3 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 2372efd3da1ccb226b4297222e25f41ecc84821d is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-1894). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.6
VulDB Meta Temp Score: 6.5

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.9
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CryptoLib 1.4.3
Patch: 2372efd3da1ccb226b4297222e25f41ecc84821d

Timelineinfo

01/05/2026 CVE reserved
01/10/2026 +5 days Advisory disclosed
01/10/2026 +0 days VulDB entry created
01/17/2026 +7 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-4g6v-36fv-qcvw
Status: Confirmed

CVE: CVE-2026-21900 (🔒)
GCVE (CVE): GCVE-0-2026-21900
GCVE (VulDB): GCVE-100-340401
EUVD: 🔒

Entryinfo

Created: 01/10/2026 10:31
Updated: 01/17/2026 05:46
Changes: 01/10/2026 10:31 (72), 01/11/2026 02:54 (1), 01/17/2026 05:46 (11)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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