CVE-2026-48164: CollaboraOnline online · Cross-site Scripting
Affects CollaboraOnline onlineSource CVE Database V5
Not known to be exploited · CVSS 4.7 Medium : upgrade to 25.04.11 or 24.04.18 when convenient.
Data as of 30 Oct 2026, 15:18 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 4.7 |
|---|
- Patch
- Available – fixed in 25.04.11, 24.04.18
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade CollaboraOnline online to 25.04.11 or 24.04.18.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CollaboraOnlineonline | Affected
| Fixed in
|
| CollaboraOnlineonline | Affected
| Fixed in
|
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.