CVE-2026-55499Public exploitNetwork attack vector

Authenticated metadata disclosure via parent-topic subscription

Published Jul 31, 2026 · Updated Jul 31, 2026

Incorrect authorization in Cloudreve before 4.17.0 allows remote authenticated users to read unshared sibling file-activity metadata. The ExplorerEventService subscribes a single-file share root to the owner parent folder topic, and event fan-out never checks the subscriber share scope. Exploitation requires an authenticated single-file share recipient and the event hub, which is enabled by default; it exposes names, paths, rename targets, event types, and hashed identifiers, but not file contents.

CVSS severity4.3
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Cloudreve before 4.17.0 allows remote authenticated users to read unshared sibling file-activity metadata. The ExplorerEventService subscribes a single-file share root to the owner parent folder topic, and event fan-out never checks the subscriber share scope. Exploitation requires an authenticated single-file share recipient and the event hub, which is enabled by default; it exposes names, paths, rename targets, event types, and hashed identifiers, but not file contents.

The record

CVE
CVE-2026-55499
Published
Jul 31, 2026
Updated
Jul 31, 2026
Vendor
Cloudreve
Product
Cloudreve
Classifications
CWE-863, T1530
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.17.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Cloudreve · Cloudreveversion=< 4.17.0

Published CVSS scores

4.3GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1530Data from Cloud Storage

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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