CVE-2026-62323

Cloudreve: Unauthorized file write via WOPI view sessions whose access token secret is ignored

MEDIUM
6.3
CVSS Score
Published: July 31, 2026 at 03:43 AM UTC
Updated: September 8, 2026 at 09:09 PM UTC
1 product affected across 1 vendorCloudreve

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Severity
MEDIUM6.3
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, ViewerSessionValidation uses only the session-id prefix of a WOPI access token and does not enforce the requested viewer action, allowing a malicious or compromised WOPI viewer with a view session to forge the token suffix and invoke WOPI write routes for the underlying file. This issue is fixed in version 4.17.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.17.0
Affected range stops below 4.17.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-863

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