CVE-2026-46499: medium-severity vulnerability in CollaboraOnline online
Collabora Online: Read-only session authorization bypass permits live document edits
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.3epss 0.2%
Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to 24.04.18 and 25.04.11, several document operations delegated to `LibreOfficeKit` in the per-document kit process fail to enforce a session's read-only state. A read-only user, such as a viewer-role WOPI user, can send crafted `WebSocket` messages to execute document-mutating `UNO` commands and dialog operations despite the read-only interface. The changes can mislead co-viewers within the live session, or an authorized editor sharing the session can unknowingly save the modifications. The read-only attacker cannot save the document directly, and changes are discarded when the kit session ends unless an authorized editor saves them. This issue is fixed in versions 24.04.18 and 25.04.11.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Affected products
CollaboraOnline · onlineRelated CVEs — CollaboraOnline online
In the same product, most dangerous first.
CVE-2025-66208HIGHConfiguration-Dependent RCE (OS Command Injection) in richdocumentscode proxyEPSS 1.8%CVE-2021-32744CRITICALUnauthenticated attacker could gain access to currently open filesEPSS 1.1%CVE-2021-43817HIGHReflected Cross-Site-Scripting vulnerability in Collabora OnlineEPSS 0.7%CVE-2021-32745HIGHReflected Cross-Site-Scripting vulnerabilityEPSS 0.6%CVE-2025-24796MEDIUMRemote Code Execution within Collabora Online jail with Macros EnabledEPSS 0.5%CVE-2023-49788HIGHImproper handling of browser-side provided input in richdocuments path handlingEPSS 0.5%