Security assessments indicate that CVE-2026-21900 presents a notable risk, potentially requiring prompt mitigation.
Status: Analyzed
Last updated: 🕟 16 Jan 2026, 16:46 UTC
Originally published on: 🕐 10 Jan 2026, 01:16 UTC
Time between publication and last update: 6 days
CVSS Release: version 3
nvd@nist.gov
Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVE-2026-21900: 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 exploitability of CVE-2026-21900 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2026-21900 presents a challenge to exploit due to its high attack complexity, but the absence of privilege requirements still makes it a viable target for skilled attackers. A thorough security review is advised.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-21900, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-21900, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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