CVE-2026-40319 Giskard has a Regular Expression Denial of Service (ReDoS) in RegexMatching Check
An attacker with write access to check definitions can cause indefinite process hangs via catastrophic backtracking in RegexMatching checks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-40319?
CVE-2026-40319 is a low-severity denial of service vulnerability in Giskard-AI giskard-oss, published on 17 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-1333
Which versions are affected by CVE-2026-40319?
3 open source packages ship an affected version, including giskard-checks. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
giskard-checks PyPI | All versions | 1.0.2b1 |
giskard-checks PyPI | All versions | 1.0.2b1 |
giskard-checks PyPI | All versions | 1.0.2b1 |
Products include Giskard Giskard.
How do I fix CVE-2026-40319?
Upgrade giskard-checks to 1.0.2b1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-40319 being exploited?
There is no known exploitation of CVE-2026-40319 in the wild and no public exploit code.
Other vulnerabilities in Giskard-AI giskard-oss
Sources
Also known as GHSA-rq2q-4r55-9877, PYSEC-2026-2489.