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TI-2026-44495 Aliases CVE-2026-62323GHSA-c3jm-gv5r-9wcp

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

Priority MEDIUM 61CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-863.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00306 23rd percentileScored 2026-11-07
Fix Fixed cloudreve (cloudreve): 4.17.0github.com/cloudreve/Cloudreve/v4 (Go): 4.0.0-20260626022433-f3347130ac48

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
cloudrevecloudrevebefore 4.17.04.17.0Patch availableCNA
—github.com/cloudreve/Cloudreve/v4 (Go)before 4.0.0-20260626022433-f3347130ac484.0.0-20260626022433-f3347130ac48Patch availableGHSA-c3jm-gv5r-9wcp
—github.com/cloudreve/Cloudreve/v3 (Go)up to 3.0.0-20250225100611-da4e44b77af4—No fix listedGHSA-c3jm-gv5r-9wcp
  • cloudreve Vendorcloudreve Affected before 4.17.0 Fixed in 4.17.0 Patch available CNA
  • github.com/cloudreve/Cloudreve/v4 (Go) Vendor— Affected before 4.0.0-20260626022433-f3347130ac48 Fixed in 4.0.0-20260626022433-f3347130ac48 Patch available GHSA-c3jm-gv5r-9wcp
  • github.com/cloudreve/Cloudreve/v3 (Go) Vendor— Affected up to 3.0.0-20250225100611-da4e44b77af4 Fixed in — No fix listed GHSA-c3jm-gv5r-9wcp

Remediation

  • Fix · CNA cloudreve (cloudreve) Fixed in 4.17.0
  • Fix · GHSA-c3jm-gv5r-9wcp github.com/cloudreve/Cloudreve/v4 (Go) Fixed in 4.0.0-20260626022433-f3347130ac48 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-62323
  2. 2026-10-03 Alias added: GHSA-c3jm-gv5r-9wcp

References

Other 4

  • TI-2026-65089 Cloudreve before 4.16.1 Authentication Bypass via Cached Context Hint CVSS 4.0MEDIUM 6.9
  • TI-2026-39397 Cloudreve: OAuth access tokens bypass scope enforcement due to missing client_id claim CVSS 3.1HIGH 7.6
  • TI-2026-40054 Cloudreve: OAuth Admin.Read scope can update OneDrive storage policy credentials CVSS 3.1HIGH 7.1
  • TI-2026-39400 Incorrect authorization in cloudreve CVSS 3.1HIGH 7.1
  • TI-2026-40050 Cloudreve: Server crash through image decompression/pixel bomb in thumbnail & avatar decoding (DoS) CVSS 3.1MEDIUM 6.5
  • TI-2026-39399 Cloudreve: Non-admin remote download users can SSRF loopback/internal services and read imported responses CVSS 3.1MEDIUM 6.5
See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences