{"cve":"CVE-2021-26929","nvd":{"published":"2021-02-14T04:15:12.777","modified":"2026-06-17T03:44:01.673","status":"Modified","description":"An XSS issue was discovered in Horde Groupware Webmail Edition through 5.2.22 (where the Horde_Text_Filter library before 2.3.7 is used). The attacker can send a plain text e-mail message, with JavaScript encoded as a link or email that is mishandled by preProcess in Text2html.php, because bespoke use of \\x00\\x00\\x00 and \\x01\\x01\\x01 interferes with XSS defenses.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79"],"references":["http://packetstormsecurity.com/files/162187/Webmail-Edition-5.2.22-XSS-Remote-Code-Execution.html","http://packetstormsecurity.com/files/162194/Horde-Groupware-Webmail-5.2.22-Cross-Site-Scripting.html","https://github.com/horde/webmail/releases","https://lists.debian.org/debian-lts-announce/2021/02/msg00028.html","https://lists.horde.org/archives/announce/2021/001298.html"],"products":["debian:debian_linux","horde:groupware"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-26929","score":0.04944,"percentile":0.92156,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}