Quick answers
- Is CVE-2026-40571 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-40571 being exploited in the wild.
- How severe is CVE-2026-40571?
- Informational severity, with a CVSS score of 5.3, published 2 June 2026.
- Which products and versions are affected?
- NamelessMC 2.2.4.
- Is there a fix for CVE-2026-40571?
- A patch was published on 2026-06-02: Version 2.2.5 released with fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-40571 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-40571?
- Check whether you run NamelessMC 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 missing authorization check (CWE-862) exists in the `ProfilePostReactionContext.php` component of NamelessMC version 2.2.4. The `validateReactable()` function verifies that a wall post exists but fails to enforce visibility restrictions related to private profiles or user blocks. An authenticated attacker with low privileges can bypass these intended access controls by sending a crafted POST request to the `/queries/reactions` endpoint. This allows the attacker to add reactions to posts they are not authorized to view. The vulnerability is addressed in version 2.2.5 by enforcing proper authorization checks and returning generic errors to prevent information leakage.
Affected products
- NamelessMC NamelessMC 2.2.4
Timeline
- 2026-05-31: advisory: GitHub Security Advisory published by vendor
- 2026-06-02: disclosed: CVE published to NVD
- 2026-06-02: patched: Version 2.2.5 released with fix