CVE-2026-77633

Published: Set 22, 2026 Last Modified: Set 22, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: low
Availability: high

Description

AI Translation Available

Cloudreve is a self-hosted file management and sharing system. Prior to 4.18.0, PrepareUpload in pkg/filemanager/fs/dbfs/upload.go checks a stale in-memory user storage value through validateUserCapacity and later applies an unconditional storage charge outside the same quota-enforcing transaction. An authenticated user with Files.Write permission can issue concurrent upload-session requests that read the same capacity snapshot, all pass the MaxStorage check, and reserve their declared sizes through CommitWithStorageDiff. The resulting reservations can exceed the account quota and can be materialized as chunked uploads that exhaust host storage and deny uploads to other users. The default local-storage policy and default User group are affected. This issue is fixed in version 4.18.0.

362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Draft
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Confidentiality Integrity Access Control
Potential Impacts:
Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Resource Consumption (Other) Dos: Crash, Exit, Or Restart Dos: Instability Read Files Or Directories Read Application Data Execute Unauthorized Code Or Commands Gain Privileges Or Assume Identity Bypass Protection Mechanism
Applicable Platforms
Languages: C, C++, Java
Technologies: Mobile, ICS/OT
Likelihood of Exploit: Medium
View CWE Details
367

Time-of-check Time-of-use (TOCTOU) Race Condition

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Other Non-Repudiation
Potential Impacts:
Alter Execution Logic Unexpected State Modify Application Data Modify Files Or Directories Modify Memory Other Hide Activities
Applicable Platforms
All platforms may be affected
Likelihood of Exploit: Medium
View CWE Details
770

Allocation of Resources Without Limits or Throttling

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Availability
Potential Impacts:
Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Resource Consumption (Other)
Applicable Platforms
All platforms may be affected
Likelihood of Exploit: High
View CWE Details
https://github.com/cloudreve/cloudreve/commit/7329602751c00…
https://github.com/cloudreve/cloudreve/commit/7329602751c00bb4136fe9ad8b364d0df…
https://github.com/cloudreve/cloudreve/releases/tag/4.18.0
https://github.com/cloudreve/cloudreve/releases/tag/4.18.0
https://github.com/cloudreve/cloudreve/security/advisories/…
https://github.com/cloudreve/cloudreve/security/advisories/GHSA-xj3h-wwxq-gfcj