CVE-2026-71249

medium
Published 2026-08-05 · Modified 2026-08-05
CVSS v3
6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4 NEW
not yet in upstream
VIR risk
6.1

Description

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. An unauthenticated attacker can submit a payload such as name="><script>alert(document.domain)</script> to achieve reflected XSS against any visitor who submits or is tricked into auto-submitting the form, including a targeted administrator, enabling session token theft.

Predictions

Exploit likelihood
71%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-79

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.