What is CVE-2026-40319?

CVE-2026-40319 is a medium-severity vulnerability in Giskard, classified under Inefficient Regular Expression Complexity. CVSS score: 5.5/10. Published 2026-04-17.

How severe is CVE-2026-40319?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Giskard

CVE-2026-40319

Giskard is an open-source testing framework for AI models. In versions prior to 1.0.2b1, the RegexMatching check passes a user-supplied regular expression pattern directly to Python's re.search() without any timeout or complexity guard. A crafted regex pattern can trigger catastrophic backtracking, causing the process to hang indefinitely. Exploitation requires write access to a check definition and subsequent execution of the test suite. This issue has been fixed in giskard-checks version 1.0.2b1.

Vulnerability class: ReDoS (Regular Expression Denial of Service)

EPSS: 0.001 (4.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Giskard
Giskard-ai Giskard-oss — versions < 1.0.2b1

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2026-40319?: CVE-2026-40319 is a medium-severity vulnerability in Giskard, classified under Inefficient Regular Expression Complexity. CVSS score: 5.5/10. Published 2026-04-17.
How severe is CVE-2026-40319?: Medium severity. CVSS v3 base score is 5.5 out of 10.