RCE in Piwigo
CVE-2026-78187
A vulnerability has been found in Piwigo 16.3.0. This impacts an unknown function of the component Public Authentication Page. Such manipulation of the argument lang leads to cross site scripting. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is said to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 16.4.0 will fix this issue. The name of the patch is 5277a7dee4b8f1a174f1d69e1e2a4e1c82a3fc9e. It is recommended to upgrade the affected component.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.007 (49.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.002
Affected products
- Piwigo — versions 16.3.0
Weakness classification (CWE)
References
- vuldb.com/vuln/394569 (technical-description, vdb-entry)
- vuldb.com/vuln/394569/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-78187 (third-party-advisory)
- vuldb.com/submit/885228 (third-party-advisory)
- github.com/Piwigo/Piwigo/security/advisories/GHSA-rr39-mf4j-6594 (related)
- github.com/Leousum/VulnPoC/blob/main/Piwigo 16.3.0/reflected_XSS.md (exploit)
- github.com/Piwigo/Piwigo/commit/5277a7dee4b8f1a174f1d69e1e2a4e1c82a3fc9e (patch)
- github.com/Piwigo/Piwigo/releases/tag/16.4.0 (patch)
- github.com/Piwigo/Piwigo/ (product)
Frequently asked questions
- What is CVE-2026-78187?
- CVE-2026-78187 is a low-severity vulnerability in Piwigo, classified under Cross-site Scripting. CVSS score: 3.1/10. Published 2026-08-24.
- How severe is CVE-2026-78187?
- Low severity. CVSS v3 base score is 3.1 out of 10.