CVE-2026-40319

The RegexMatching check in the giskard-checks package passes a user-supplied regular expression pattern directly to Python's re.search() without any timeout, complexity guard, or pattern validation. An attacker who can control the regex pattern or the text being matched can craft inputs that trigger catastrophic backtracking in the regex engine, causing the process to hang indefinitely and denying service to all other operations.

giskard-checks is a local developer testing library. Check definitions, including the pattern parameter, are provided in application code or configuration files and executed locally. Exploitation requires write access to a check definition and subsequent execution of the test suite. The absence of a regex timeout could cause availability issues in automated environments such as CI/CD pipelines.

Affected component

text_matching.py, line 457: re.search(pattern, text)

Credit

Giskard-AI thanks @dhabaleshwar for identifying the missing timeout on regex evaluation.

A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use. Typical impact: denial of service when input is crafted to trigger backtracking.

CVE-2026-40319 has a CVSS score of 5.5 (Low). The vector is requires local access, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.0.2b1); upgrading removes the vulnerable code path.

Kodem intelligence

Upgrade to giskard-checks >= 1.0.2b1.

1. What is CVE-2026-40319? CVE-2026-40319 is a low-severity inefficient regular expression (ReDoS) vulnerability in giskard-checks (pip), affecting versions <= 1.0.1b1. It is fixed in 1.0.2b1. A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use.
2. How severe is CVE-2026-40319? CVE-2026-40319 has a CVSS score of 5.5 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of giskard-checks are affected by CVE-2026-40319? giskard-checks (pip) versions <= 1.0.1b1 is affected.
4. Is there a fix for CVE-2026-40319? Yes. CVE-2026-40319 is fixed in 1.0.2b1. Upgrade to this version or later.
5. Is CVE-2026-40319 exploitable, and should I be worried? Whether CVE-2026-40319 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-40319 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-40319? Upgrade giskard-checks to 1.0.2b1 or later.

Other vulnerabilities in giskard-checks