{"id":"CVE-2026-48164","aliases":["EUVD-2026-114089","GHSA-wgmm-q3ch-64jj"],"status":"published","title":"Collabora Online: Reflected HTML injection through host_session_id","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.","severity":{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00325,"percentile":0.25759,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-10-30T14:57:18Z","modified":"2026-11-01T07:03:04Z","products":[{"vendor":"collaboraonline","product":"online"}],"references":[{"url":"https://github.com/CollaboraOnline/online/security/advisories/GHSA-wgmm-q3ch-64jj","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/CollaboraOnline/online/commit/2d4469d27f0c52f4b28b64090e60452d2e147279","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48164.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48164","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-48164","title":"Collabora Online: Reflected HTML injection through host_session_id","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.","status":"published","published":"2026-10-30T14:57:18.378Z","modified":"2026-10-30T15:44:29.766Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T13:50:38.739766Z"}],"euvd":[{"id":"EUVD-2026-114089","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.","status":"published","published":"2026-10-30T14:57:18Z","modified":"2026-10-30T15:44:29Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T16:59:06.268136Z"}],"nvd":[{"id":"CVE-2026-48164","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.","status":"published","published":"2026-10-30T15:16:52.217Z","modified":"2026-10-30T19:37:07.073Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:13:05.268617Z"}],"osv":[{"id":"CVE-2026-48164","title":"Collabora Online: Reflected HTML injection through host_session_id","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.","status":"published","published":"2026-10-30T14:57:18.378Z","modified":"2026-11-01T07:03:04.49610211Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:06.701612Z"}]}}