๐Ÿ” CVE Alert

CVE-2026-46499

MEDIUM 4.3

Collabora Online: Read-only session authorization bypass permits live document edits

CVSS Score
4.3
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-863
Vendor collaboraonline
Product online
Published Oct 30, 2026
Stay Ahead of the Next One

Get instant alerts for collaboraonline online

Be the first to know when new medium vulnerabilities affecting collaboraonline online are published โ€” delivered to Slack, Telegram or Discord.

Get Free Alerts โ†’ Free ยท No credit card ยท 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

Affected Versions

CollaboraOnline / online
< 24.04.18 >= 25.04.0-0, < 25.04.11

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/CollaboraOnline/online/security/advisories/GHSA-27j2-3cqv-cc5q