CVE-2026-34206
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk9th percentile - higher than 9% of all known CVEs
Summary
Captcha Protect, a Traefik middleware, is vulnerable to reflected XSS. The challenge page accepts a client-supplied destination value and renders it into HTML using Go's text/template, which does not perform contextual HTML escaping.
Risk Assessment
An attacker can inject arbitrary script that executes in the victim's browser, potentially leading to data theft or session hijacking.
Recommendation
Update Captcha Protect to version 1.12.2, which contains the fix.
Original NVD description (English source)
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.