CVE-2026-101056

Cloudreve before 4.16.1 Authentication Bypass via Cached Context Hint

Published Sep 27, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

Description

Cloudreve before 4.16.1 fails to revalidate share access when restoring cached navigator state from a context_hint UUID. Attackers who previously had valid share access can replay the cached hint to generate signed file URLs for up to 300 seconds after the share is deleted, expires, or reaches zero remaining downloads.

Analysis

Technical impact

Cloudreve versions before 4.16.1 do not revalidate share access when restoring a cached navigator state from a context_hint UUID. Attackers who previously had valid share access can replay the cached hint to generate signed file URLs for up to 300 seconds after the share is deleted, expires, or reaches zero remaining downloads, enabling unauthorized access to shared files.

Affected Systems

The vulnerability affects all installations of Cloudreve earlier than version 4.16.1, regardless of deployment environment or operating system.

Risk and Exploitability

The CVSS score of 6.9 indicates a medium severity, and the EPSS score is not available. The vulnerability is not listed in the CISA KEV catalog. Based on the description, the likely attack vector is an attacker with prior valid share access replaying a cached context hint; no external exploitation path is described. The risk is that such a replay can provide temporary unauthorized authenticated file access.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

cloudreve

unaffected

Version	Status	Constraints
`0`	affected	< 4.16.1
`4.16.1`	unaffected	—

No data.

Vendor Product Versions

Cloudreve

Version	Status	Scheme	Platform
`[0,4.16.1)`	affected	semver	—
`4.16.1`	unaffected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade Cloudreve to version 4.16.1 or later.
Invalidate all revoked or expired shares and disable reuse of cached context hints for those shares.
Implement monitoring of signed URL generation to detect anomalous pattern after share expiration.

Generated by OpenCVE AI on September 27, 2026 at 18:22 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.195% probability within 30 days)

Exploitation poc

Automatable yes

Technical Impact partial

References

Link	Providers
https://github.com/cloudreve/cloudreve/security/advisories/GHSA-vx2m-jpxr-xv7w
https://www.vulncheck.com/advisories/cloudreve-before-4.16.1-authentication-bypass-via-cached-context-hint

History

Sep 28, 2026 2:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 27, 2026 5:30 PM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		Cloudreve before 4.16.1 fails to revalidate share access when restoring cached navigator state from a context_hint UUID. Attackers who previously had valid share access can replay the cached hint to generate signed file URLs for up to 300 seconds after the share is deleted, expires, or reaches zero remaining downloads.
Title		Cloudreve before 4.16.1 Authentication Bypass via Cached Context Hint
First Time appeared		Cloudreve Cloudreve cloudreve
Weaknesses		CWE-863
CPEs		cpe:2.3:a:cloudreve:cloudreve::::::::
Vendors & Products		Cloudreve Cloudreve cloudreve
References		https://github.com/cloudreve/cloudreve/security/advisories/GHSA-vx2m-jpxr-xv7w https://www.vulncheck.com/advisories/cloudreve-before-4.16.1-authentication-bypass-via-cached-context-hint
Metrics		cvssV3_1 `{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}` cvssV4_0 `{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}`