Skip to main content

Contest Gallery EUVDEUVD-2026-52592

| CVE-2026-16056 MEDIUM
Missing Authorization (CWE-862)
2026-08-04 WPScan GHSA-xp5w-q4v3-mxrm
4.3
CVSS 3.1 · Vendor: WPScan
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Obtain Subscriber-level WordPress account
  2. Delivery
    Identify target site runs Contest Gallery < 30.0.7
  3. Exploit
    Send authenticated HTTP request to unprotected AJAX handler
  4. Execution
    Bypass missing capability/nonce check
  5. Impact
    Retrieve full stored OpenAI prompt history

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Authorization checks on every request
MITRE ATT&CK

1 technique across 1 tactic: Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires a valid WordPress session with at minimum Subscriber-level privileges - confirmed by the CVSS vector PR:L, meaning unauthenticated visitors cannot exploit this. Additionally, the Contest Gallery plugin must be installed, active, and configured to use its OpenAI integration such that prompt history has been stored in the database. Sites with no registered users, closed registration, or no stored OpenAI prompt history have significantly reduced practical exposure. Exploitation is limited to: authenticated users with any registered WordPress role (Subscriber and above), the plugin's OpenAI feature must be in use, and the vulnerable handler must not be otherwise blocked by a WAF or security plugin. No specific platform or non-default server configuration is required beyond normal WordPress operation.

Impact

The CVSS 3.1 score of 4.3 (Medium) is well-calibrated for this issue: network-accessible (AV:N), low complexity (AC:L), but gated behind low-privilege authentication (PR:L), with impact limited strictly to confidentiality (C:L) and no integrity or availability consequences. EPSS at 0.13% (3rd percentile) signals very low probability of automated widespread exploitation. The vulnerability is absent from CISA KEV, confirming no observed active exploitation at time of analysis. However, a publicly available POC from WPScan does exist, lowering the bar for opportunistic abuse. Real-world risk is strongly context-dependent: sites whose OpenAI prompts contain proprietary business instructions, customer data, or confidential workflows face materially higher practical impact than the raw CVSS score implies. The CVSS vector and description are fully consistent - no conflicting signals observed.

Exploit ScenarioDerived

An attacker registers a free Subscriber account on a WordPress site running a vulnerable version of Contest Gallery or reuses existing low-privileged credentials. Using the publicly available WPScan proof-of-concept, they send a direct authenticated HTTP request to the unprotected AJAX endpoint, which returns the site's complete stored OpenAI prompt history without any further authorization challenge.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.1% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Aug 04, 2026

Contest Gallery WordPress plugin (all versions before 30.0.7) exposes the site's complete stored OpenAI prompt history to any authenticated user holding at minimum a Subscriber role, due to a handler that performs neither a capability check nor a nonce verification. An attacker with a basic WordPress account can call the unprotected AJAX endpoint directly to exfiltrate the full prompt history, potentially exposing confidential business logic, AI workflows, or sensitive data embedded in prompts. No active exploitation is confirmed (not in CISA KEV), but a publicly available proof-of-concept exists per WPScan, and EPSS remains low at 0.13% (3rd percentile).

RemediationAI

Upgrade the Contest Gallery WordPress plugin to version 30.0.7 or later; this release introduces proper capability and nonce verification on the vulnerable handler and is confirmed available from the vendor. If an immediate upgrade is not operationally feasible, administrators should consider temporarily deactivating the plugin to eliminate the attack surface, accepting the trade-off of losing contest functionality. As a secondary measure, disabling open WordPress user registration reduces the pool of potential attackers, though it does not protect against existing low-privileged accounts. Reviewing and rotating any sensitive information previously stored in OpenAI prompt history is advisable if the site had untrusted registered users. See the WPScan advisory at https://wpscan.com/vulnerability/53aec8d3-da17-4183-91b3-73b45681fd20/ for further details.

Affected VersionsENISA

Contest Gallery 0 <30.0.7

Affected Packages

euvd contest_gallery fix: 30.0.7

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The vulnerability is rooted in CWE-862 (Missing Authorization): the plugin registers a WordPress AJAX handler (likely via wp_ajax_ hooks) that executes without calling current_user_can() to verify appropriate permissions, and without validating a nonce to prevent cross-site request forgery. The affected product is identified by CPE cpe:2.3:a:unknown:contest_gallery:*:*:*:*:*:*:*:*, covering all versions from 0 through 30.0.6. The plugin integrates with OpenAI's API and persists AI-generated prompt history to the WordPress database; the unguarded endpoint reads and returns this stored history to any requester who presents a valid session cookie, regardless of their assigned role. WordPress's role hierarchy means Subscriber is the lowest non-anonymous tier, making this exploitable by any registered site user.

Know when Contest Gallery gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (WPScan) PRIMARY 4.3 MEDIUM
AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
vuln.today AI 4.3 MEDIUM

PR:L confirmed by Subscriber-level auth requirement; C:L reflects prompt history disclosure only; no integrity or availability impact applies.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (WPScan).

CVSS VectorVendor: WPScan

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

Lifecycle Timeline

3
Patch available
Aug 04, 2026 - 07:01 EUVD
CVE Published
Aug 04, 2026 - 06:00 cve.org
UNKNOWN (no severity yet)
CVE Published
Aug 04, 2026 - 06:00 cve.org
MEDIUM 4.3

DescriptionCVE.org

The Contest Gallery WordPress plugin before 30.0.7 does not perform any capability or nonce check in one of its handlers, allowing any authenticated user down to Subscriber to read the site's entire stored OpenAI prompt history.

Threat Intelligence Overview

EPSS Score
0.1%
Top 97% exploitable
Prevalence
Low
niche WordPress contest/gallery plugin, limited enterprise footprint
Exploit
POC
Public exploit code exists
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC Yes
EPSS 0.1%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
No
Human Impact· derived
Medium
Technical Impact
Partial

Priority Score

42
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +22
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

CVE-2021-24915 CRITICAL POC
9.8 Nov 29

The Contest Gallery WordPress plugin before 13.1.0.6 does not have capability checks and does not sanitise or escape the

CVE-2024-43283 MEDIUM POC
5.3 Aug 26

Insertion of Sensitive Information Into Sent Data vulnerability in Wasiliy Strecker / ContestGallery developer Contest G

CVE-2026-16055 HIGH POC
7.5 Aug 05

Contest Gallery WordPress plugin before version 30.0.7 implements a custom front-end login mechanism that issues authent

CVE-2022-4158 HIGH POC
7.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

CVE-2022-4156 HIGH POC
7.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

CVE-2026-16057 MEDIUM POC
6.5 Aug 03

Post-deletion authorization bypass in the Contest Gallery WordPress plugin before 30.0.7 allows any authenticated Author

CVE-2022-4166 MEDIUM POC
6.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

CVE-2022-4165 MEDIUM POC
6.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

CVE-2022-4164 MEDIUM POC
6.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

CVE-2022-4163 MEDIUM POC
6.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

CVE-2022-4162 MEDIUM POC
6.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

CVE-2022-4161 MEDIUM POC
6.5 Dec 26

The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy