6.3
MEDIUM CVSS 3.1
CVE-2026-62323
Cloudreve: Unauthorized file write via WOPI view sessions whose access token secret is ignored
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.

INFO

Published Date :

July 31, 2026, 4:17 a.m.

Last Modified :

July 31, 2026, 4:17 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-62323 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Cloudreve cloudreve
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Cloudreve to version 4.17.0 or later to fix the WOPI access token validation vulnerability.
  • Update Cloudreve to version 4.17.0.
  • Ensure WOPI access token validation is enforced.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-62323.

URL Resource
https://github.com/cloudreve/cloudreve/commit/f3347130ac48f2ff996af9ef66c97be2dda9cba9
https://github.com/cloudreve/cloudreve/releases/tag/4.17.0
https://github.com/cloudreve/cloudreve/security/advisories/GHSA-c3jm-gv5r-9wcp
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-62323 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-62323 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-62323 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-62323 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 31, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'cloudreve', 'product': 'cloudreve', 'versions': [{'status': 'affected', 'version': '< 4.17.0'}]}]
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N
    Added CWE CWE-863
    Added Reference https://github.com/cloudreve/cloudreve/commit/f3347130ac48f2ff996af9ef66c97be2dda9cba9
    Added Reference https://github.com/cloudreve/cloudreve/releases/tag/4.17.0
    Added Reference https://github.com/cloudreve/cloudreve/security/advisories/GHSA-c3jm-gv5r-9wcp
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.