CVE-2026-22026 is a vulnerability classified under CWE-789 (Memory Allocation with Excessive Size Value) found in NASA's CryptoLib, a software-only implementation of the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP). This library secures communications between spacecraft running the core Flight System (cFS) and ground stations. The vulnerability exists in the libcurl write_callback function used by the Key Management Client (KMC) crypto service client, which handles HTTP responses from the KMC server. Prior to version 1.4.3, this callback function reallocates memory buffers to accommodate incoming data without imposing any upper limit or performing overflow checks on the size. Consequently, a malicious or compromised KMC server can send an excessively large HTTP response, forcing the client to allocate memory continuously until system resources are exhausted and the process is terminated by the operating system. This results in a denial-of-service (DoS) condition, impacting the availability of the client system. The vulnerability can be exploited remotely without requiring authentication or user interaction, increasing its risk profile. Although no known exploits are currently reported in the wild, the vulnerability's presence in critical space communication software underscores the importance of timely patching. The issue was addressed in CryptoLib version 1.4.3 by implementing proper size checks and limiting memory allocation to prevent unbounded growth.

For European organizations involved in aerospace, satellite communications, or space research that utilize NASA's CryptoLib or derivatives thereof, this vulnerability poses a significant risk to the availability of critical communication systems. Exploitation could lead to denial-of-service conditions, disrupting command and control communications between spacecraft and ground stations. This disruption could delay mission-critical operations, data transmissions, or system updates, potentially causing operational setbacks or safety concerns. While confidentiality and integrity are not directly compromised by this vulnerability, the loss of availability in space communication systems can have cascading effects on dependent infrastructure and services. European space agencies, aerospace contractors, and research institutions relying on vulnerable versions of CryptoLib must consider the operational impact of potential service interruptions. Additionally, organizations integrating this library into broader systems should assess the risk of cascading failures or resource exhaustion in interconnected components. The lack of known exploits in the wild suggests limited immediate threat, but the ease of exploitation and high impact warrant proactive mitigation.

The primary mitigation is to upgrade NASA's CryptoLib to version 1.4.3 or later, where the vulnerability has been patched by adding size limits and overflow checks in the libcurl write_callback function. Organizations should audit their software supply chain and deployed systems to identify any instances of CryptoLib versions earlier than 1.4.3, especially within KMC crypto service clients. Implement network-level protections such as strict firewall rules and allowlisting to restrict communications to trusted KMC servers, reducing exposure to malicious or compromised servers. Employ runtime monitoring and resource usage alerts to detect abnormal memory consumption patterns indicative of exploitation attempts. Where possible, sandbox or isolate the KMC client processes to limit the impact of crashes or resource exhaustion on broader system stability. Conduct regular vulnerability scanning and penetration testing focused on space communication components to identify and remediate similar memory allocation issues. Finally, maintain close coordination with NASA and relevant aerospace cybersecurity authorities for updates and threat intelligence related to CryptoLib and associated protocols.