Quick answers
- Is CVE-2026-78187 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-78187 being exploited in the wild.
- How severe is CVE-2026-78187?
- Low severity, with a CVSS score of 3.1, published 24 August 2026.
- Which products and versions are affected?
- Piwigo 16.3.0.
- Is there a fix for CVE-2026-78187?
- 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-2026-78187 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-78187?
- Check whether you run Piwigo 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
This is a reflected XSS vulnerability in Piwigo's Public Authentication Page component, specifically in how it handles the 'lang' argument. The vulnerability stems from insufficient input validation or output encoding of the lang parameter. The attack is network-based and requires high complexity (likely user interaction, such as clicking a malicious link), but no authentication is required to exploit it. An attacker can inject arbitrary JavaScript code that executes in the victim's browser within the context of the Piwigo application. The vulnerability has been patched in version 16.4.0 (commit 5277a7dee4b8f1a174f1d69e1e2a4e1c82a3fc9e), and users should upgrade immediately.
Affected products
- Piwigo Piwigo 16.3.0
Timeline
- 2026-08-24: disclosed