cvedb.io
CVE-2026-26028
MEDIUM · CVSS 6.1
EPSS exploitation probability: 0%
Published 2026-05-20T20:16:36.760 · Last modified 2026-06-17T10:25:37.640

Summary

CryptPad is an end-to-end encrypted collaborative office suite. In versions prior to 2026.2.0, the HTML sanitizer in Diffmarked.js can be bypassed due to incomplete attribute filtering on restricted tags. The sanitizer validates only the src attribute of <iframe>, <video>, and <audio> elements, leaving all other attributes unchecked. As a result, an attacker can inject arbitrary HTML through srcdoc, completely defeating CryptPad's intended bounce sandboxing and enabling link injection or other interactive content within user-controlled documents. The root cause lies in how the sanitizer classifies and enforces tag restrictions: although it defines both forbidden and restricted tag lists, <iframe> is treated as "restricted" rather than "forbidden." Enforcement then inspects only the src att

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.