CVE-2026-3531Network attack vector

Authentication bypass via retained Identity Provider session

Published Mar 26, 2026 · Updated Mar 26, 2026

Authentication bypass in Drupal OpenID Connect / OAuth client before 1.5.0 allows remote authenticated users to gain Drupal access. After Drupal denies access through custom code or a server error, the module leaves the Identity Provider session active instead of ending it. A successful Identity Provider login and a subsequent Drupal denial are required; retained sessions are especially exposed on shared computers.

CVSS severity6.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Drupal OpenID Connect / OAuth client before 1.5.0 allows remote authenticated users to gain Drupal access. After Drupal denies access through custom code or a server error, the module leaves the Identity Provider session active instead of ending it. A successful Identity Provider login and a subsequent Drupal denial are required; retained sessions are especially exposed on shared computers.

The record

CVE
CVE-2026-3531
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
Avatar Uploader Project
Product
OpenID Connect / OAuth client
Classifications
CWE-288, CAPEC-115, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 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=0.0.0 <1.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Avatar Uploader Project · OpenID Connect / OAuth clientversion=0.0.0 <1.5.0

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-288Authentication Bypass Using an Alternate Path or Channel
CAPEC-115Authentication Bypass
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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