6.9
MEDIUM CVSS 4.0
CVE-2026-41509
Integer underflow in crypto_sign_open() leads to buffer overflow
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.

INFO

Published Date :

May 8, 2026, 2:16 p.m.

Last Modified :

May 8, 2026, 2:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-41509 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Patch the buffer overflow vulnerability by updating the software to the fixed version.
  • Update the software to the version after commit fc6b7e7.
  • Apply the patch for crypto_sign_open() function.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-41509.

URL Resource
https://github.com/CROSS-signature/CROSS-implementation/commit/fc6b7e78cdf789bb5c395a81dc601356f1383da0
https://github.com/CROSS-signature/CROSS-implementation/security/advisories/GHSA-w72c-hgx8-p7cv
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-41509 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-41509 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-41509 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-41509 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 08, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 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
    Added CWE CWE-121
    Added CWE CWE-122
    Added Reference https://github.com/CROSS-signature/CROSS-implementation/commit/fc6b7e78cdf789bb5c395a81dc601356f1383da0
    Added Reference https://github.com/CROSS-signature/CROSS-implementation/security/advisories/GHSA-w72c-hgx8-p7cv
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.