CVE-2026-41509 Integer underflow in crypto_sign_open() leads to buffer overflow
An integer underflow in the CROSS signature library causes a buffer overflow, potentially allowing attackers to execute arbitrary code or crash the application.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-41509?
CVE-2026-41509 is a medium-severity vulnerability in CROSS-signature CROSS-implementation, published on 8 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Which versions are affected by CVE-2026-41509?
It affects 1 product.
Products include Cross-Crypto Cross-Implementation.
How do I fix CVE-2026-41509?
No fix has been published for CVE-2026-41509 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-41509 being exploited?
There is no known exploitation of CVE-2026-41509 in the wild and no public exploit code.
Sources
Also known as GHSA-w72c-hgx8-p7cv.