Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M
CVE-2026-34206Captcha Protect: Reflected XSS in challenge page via unsanitized destination rendered with text/template
Medium 6.1
In plain English
A medium-severity cross-site scripting in captcha-protect from libops. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities).
Official description
Captcha Protect is a Traefik middleware to add an anti-bot challenge to individual IPs in a subnet when traffic spikes are detected from that subnet. Prior to version 1.12.2, a reflected cross-site scripting (XSS) vulnerability exists in github.com/libops/captcha-protect. The challenge page accepted a client-supplied destination value and rendered it into HTML using Go's text/template. Because text/template does not perform contextual HTML escaping, an attacker could supply a crafted destination value that breaks out of the hidden input attribute and injects arbitrary script into the challenge page. This issue has been patched in version 1.12.2.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| libops | captcha-protect | < 1.12.2 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N