Cyber Resilience

CVE-2026-21898

Memory Safety in Nasa Cryptolib ≤ 1.4.3

Public PoCMemory Safety
Published
10 January 2026
Modified
15 January 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
EPSS Score 0.0042 35th percentile
Risk Priority 61 floored blend · peak EPSS

Summary

CVE-2026-21898 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Nasa Cryptolib. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 35th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-21898 is a memory safety vulnerability in NASA's CryptoLib, a software-only library implementing the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) for securing communications between spacecraft running the core Flight System (cFS) and ground stations. Specifically, versions prior to 1.4.3 suffer from an out-of-bounds read in the Crypto_AOS_ProcessSecurity function during parsing of AOS frame hashes, due to a lack of valid bounds checking (CWE-125). This flaw has a CVSS v3.1 base score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H), indicating high severity primarily from availability impact.

A remote, unauthenticated attacker with network access to the affected system can exploit this vulnerability with low complexity and no user interaction required. By sending specially crafted AOS frames containing malformed hashes, the attacker triggers the out-of-bounds memory read, potentially leading to application crashes, denial of service, or limited information disclosure through memory contents.

The vulnerability has been addressed in CryptoLib version 1.4.3, as detailed in the project's GitHub security advisory (GHSA-7ch6-2pmg-m853) and release notes. Security practitioners using CryptoLib in spaceflight communication stacks should upgrade to v1.4.3 or later to mitigate the issue.

EU & UK References

Vulnerability Data

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_AOS_ProcessSecurity function…

more

reads memory without valid bounds checking when parsing AOS frame hashes. This issue has been patched in version 1.4.3.

CWE(s)
CWE-125

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-21899Same product: Nasa Cryptolib
CVE-2024-44911Same product: Nasa Cryptolib
CVE-2026-21900Same product: Nasa Cryptolib
CVE-2024-44912Same product: Nasa Cryptolib
CVE-2026-22023Same product: Nasa Cryptolib
CVE-2024-44910Same product: Nasa Cryptolib
CVE-2025-29913Same product: Nasa Cryptolib
CVE-2025-29912Same product: Nasa Cryptolib
CVE-2025-29911Same product: Nasa Cryptolib
CVE-2025-30216Same product: Nasa Cryptolib

Affected Assets

nasa
cryptolib
≤ 1.4.3

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.

SC-39 Process Isolation partial match

Process isolation confines the effects of an out-of-bounds read to the compromised process.

SI-10 Information Input Validation partial match

Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

A.8.26 Application security requirements partial match
prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.

References