XSS in 299ko

CVE-2026-71249

299Ko's public contact form (plugin/contact/controllers/ContactController.php, home) sets raw POST field values (name, firstname, email, message) into the page template with no sanitization. The template engine's variable output function (common/Template.php, _show_var) echoes values with no htmlspecialchars call, and the sink template (contact.tpl) outputs these values unescaped into an HTML attribute and a textarea.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (16.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 16.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-71249: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-71249?
CVE-2026-71249 is a medium-severity vulnerability in 299ko, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-08-05.
How severe is CVE-2026-71249?
Medium severity. CVSS v3 base score is 6.1 out of 10.