CVE-2026-41509 PUBLISHED

Integer underflow in crypto_sign_open() leads to buffer overflow

Assigner: GitHub_M
Reserved: 20.04.2026 Published: 08.05.2026 Updated: 08.05.2026

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.

Metrics

CVSS 4.0

CVSS Vector: 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
CVSS Score: 6.9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	Low	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	CROSS-signature
Product	CROSS-implementation
Versions	Version < fc6b7e78cdf789bb5c395a81dc601356f1383da0 is affected

References

Problem Types

CWE-121: Stack-based Buffer Overflow CWE
CWE-122: Heap-based Buffer Overflow CWE