Quick answers
- Is CVE-2026-40731 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-40731 being exploited in the wild.
- How severe is CVE-2026-40731?
- High severity, with a CVSS score of 8.1, published 17 June 2026.
- Which products and versions are affected?
- Mikado-Themes ChapterOne <= 1.7.
- Is there a fix for CVE-2026-40731?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-40731 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-40731?
- Check whether you run Mikado-Themes ChapterOne at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A Local File Inclusion (LFI) vulnerability exists in the ChapterOne WordPress theme due to improper control of filenames in PHP include/require statements (CWE-98). The flaw allows an unauthenticated remote attacker to manipulate input to include local files from the server's filesystem. While the attack complexity is rated as high, a successful exploit can lead to the disclosure of sensitive information such as wp-config.php, which contains database credentials. The vulnerability is addressed in version 1.8 of the theme.
Affected products
- Mikado-Themes ChapterOne <= 1.7
Timeline
- 2026-02-10: other: Vulnerability reported by researcher
- 2026-04-16: advisory: Initial disclosure by Patchstack
- 2026-06-17: disclosed: CVE published to NVD