{"id":"CVE-2026-34206","summary":"Captcha Protect: Reflected XSS in challenge page via unsanitized destination rendered with text/template","details":"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.","aliases":["GHSA-ph62-4j5g-2q4r"],"modified":"2026-04-02T13:41:39.361235Z","published":"2026-03-31T19:34:21.383Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34206.json","cwe_ids":["CWE-79"],"cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34206.json"},{"type":"FIX","url":"https://github.com/libops/captcha-protect/commit/eef6211ecd1147273be484d913b81c68c0bd8d3f"},{"type":"WEB","url":"https://github.com/libops/captcha-protect/releases/tag/v1.12.2"},{"type":"ADVISORY","url":"https://github.com/libops/captcha-protect/security/advisories/GHSA-ph62-4j5g-2q4r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34206"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/libops/captcha-protect","events":[{"introduced":"0"},{"fixed":"eef6211ecd1147273be484d913b81c68c0bd8d3f"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"1.12.2"}]}}],"versions":["v0.0.1","v0.0.2","v0.0.3","v0.0.4","v0.0.5","v0.1.0","v0.1.1","v0.1.2","v0.1.3","v1.0.0","v1.0.1","v1.0.2","v1.1.0","v1.1.1","v1.1.2","v1.10.0","v1.10.1","v1.11.0","v1.11.1","v1.12.0","v1.12.1","v1.2.0","v1.2.1","v1.3.0","v1.3.1","v1.3.2","v1.4.0","v1.4.1","v1.5.0","v1.6.0","v1.6.1","v1.6.2","v1.7.0","v1.7.1","v1.8.0","v1.8.1","v1.8.2","v1.9.0","v1.9.1","v1.9.2","v1.9.3","v1.9.4","v1.9.5"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34206.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}