CVE-2026-27833Public exploitNetwork attack vector

Unauthenticated visitor-history disclosure via missing API authorization

Published Apr 3, 2026 · Updated Apr 3, 2026

Missing authorization in Piwigo before 16.3.0 allows remote attackers to read every gallery visitor's browsing history through its API. The pwg.history.search registration in ws.php omits admin_only, while ws_history_search() performs no authentication check before returning history records. Default-enabled web services expose visitor IP addresses, identities, image views, downloads, and search queries without credentials.

CVSS severity7.5
High
EPSS probability1.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Piwigo before 16.3.0 allows remote attackers to read every gallery visitor's browsing history through its API. The pwg.history.search registration in ws.php omits admin_only, while ws_history_search() performs no authentication check before returning history records. Default-enabled web services expose visitor IP addresses, identities, image views, downloads, and search queries without credentials.

The record

CVE
CVE-2026-27833
Published
Apr 3, 2026
Updated
Apr 3, 2026
Vendor
Piwigo
Product
Piwigo
Classifications
CWE-862, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 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=< 16.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Piwigo · Piwigoversion=< 16.3.0

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1190Exploit Public-Facing Application

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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