---
id: CVE-2026-46499
title: >-
  Collabora Online: Read-only session authorization bypass permits live document
  edits
summary: >-
  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'…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-863
vendor: CollaboraOnline
product: online
affected:
  - online < 24.04.18
  - 'online >= 25.04.0-0, < 25.04.11'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T21:37:29.584960Z'
published: '2026-10-30'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T21:37:39.924Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-46499'
references:
  - url: >-
      https://github.com/CollaboraOnline/online/security/advisories/GHSA-27j2-3cqv-cc5q
    label: >-
      https://github.com/CollaboraOnline/online/security/advisories/GHSA-27j2-3cqv-cc5q
tags:
  - cve.org
epss: 0.00249
epssPercentile: 0.16366
ingestedAt: '2026-11-05T16:07:30.313Z'
---

## Overview

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.

## Affected

- `online < 24.04.18`
- `online >= 25.04.0-0, < 25.04.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.