Vulnerability · Published May 8, 2026 · Assigned by GitHub_M
CVE-2026-41509Integer underflow in crypto_sign_open() leads to buffer overflow
Medium 6.9
In plain English
A medium-severity stack buffer overflow in CROSS-implementation from CROSS-signature. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities).
Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.3%top 72.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| CROSS-signature | CROSS-implementation | < fc6b7e78cdf789bb5c395a81dc601356f1383da0 |
Weakness: CWE-121, CWE-122 · 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