Cyber Resilience

CVE-2026-41509

Medium

Published: 08 May 2026

Published
08 May 2026
Modified
12 May 2026
KEV Added
—
Patch
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CVSS Score v4 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0034 25.9th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-41509 is a medium-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Cross-Crypto Cross-Implementation. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 25.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

CROSS implementation contains reference and optimized implementations of the CROSS post-quantum signature algorithm. Prior to commit fc6b7e7, there is a buffer overflow in crypto_sign_open() caused by an underflow of the integer mlen. This issue has been patched via commit fc6b7e7.

CWE(s)
CWE-121CWE-122

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
Why these techniques?

Stack/heap buffer overflow in crypto_sign_open() directly enables remote code execution via memory corruption, mapping to client-side exploitation and privilege escalation.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

cross-crypto
cross-implementation
≤ 2026-03-23

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References