Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to 24.04.18 and 25.04.11, the `host_session_id` query/form parameter is substituted into the `cool.html` editor page without HTML encoding, unlike parameters passed through the existing variable-encoding mechanism. An attacker who induces a victim to load a crafted URL can inject HTML and, in the absence of an effective `Content Security Policy`, execute scripts in the Collabora Online iframe's origin, exposing the session authentication token and page contents. A reverse proxy that preserves the `Content Security Policy` header sent by `coolwsd` mitigates the script-execution scenario. This issue is fixed in versions 24.04.18 and 25.04.11.
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History
Fri, 30 Oct 2026 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to 24.04.18 and 25.04.11, the `host_session_id` query/form parameter is substituted into the `cool.html` editor page without HTML encoding, unlike parameters passed through the existing variable-encoding mechanism. An attacker who induces a victim to load a crafted URL can inject HTML and, in the absence of an effective `Content Security Policy`, execute scripts in the Collabora Online iframe's origin, exposing the session authentication token and page contents. A reverse proxy that preserves the `Content Security Policy` header sent by `coolwsd` mitigates the script-execution scenario. This issue is fixed in versions 24.04.18 and 25.04.11. | |
| Title | Collabora Online: Reflected HTML injection through host_session_id | |
| Weaknesses | CWE-79 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-10-30T15:44:29.766Z
Reserved: 2026-05-20T23:12:43.032Z
Link: CVE-2026-48164
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Status : Received
Published: 2026-10-30T15:16:52.217
Modified: 2026-10-30T15:16:52.217
Link: CVE-2026-48164
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OpenCVE Enrichment
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Weaknesses