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CVE-2026-47733

Rocket.Chat: Missing URL protocol sanitization in ImageElement allows javascript: URLs in markdown images PUBLISHED

Description (CNA)

Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.0, the ImageElement component in packages/gazzodown renders user-controlled src values directly into <a href> and <img src> attributes without protocol sanitization. Unlike the analogous LinkSpan component — which uses sanitizeUrl to block javascript:, data:, and vbscript: protocols — ImageElement passes the raw URL through unchanged. An authenticated user can post a markdown image with a javascript: URL that, if clicked on an older browser, would execute arbitrary JavaScript in the viewer's session. This vulnerability is fixed in 8.5.0.

Affected (CNA)

Vendor / productVersions
RocketChat / Rocket.Chataffected < 8.5.0

CWE

CWE-79

References

ADP enrichment

CISA-ADP

No English description supplied.