---
id: CVE-2026-67351
title: >-
  Serendipity before 2.6.1 contains an authentication context confusion
  vulnerability where password validation and session loading operate
  independently without ensuring both use the same user record
summary: >-
  Serendipity before 2.6.1 contains an authentication context confusion
  vulnerability where password validation and session loading operate
  independently without ensuring both use the same user record. An authenticated
  Editor can create a …
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-304
published: '2026-07-30'
updated: '2026-07-31'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67351'
references:
  - url: 'https://github.com/s9y/Serendipity/security/advisories/GHSA-v645-243f-jwgh'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/serendipity-authentication-bypass-via-username-collision
    label: disclosure@vulncheck.com
  - url: 'https://github.com/s9y/Serendipity/security/advisories/GHSA-v645-243f-jwgh'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00555
epssPercentile: 0.43947
ingestedAt: '2026-08-01T22:15:46.029Z'
---

## Overview

Serendipity before 2.6.1 contains an authentication context confusion vulnerability where password validation and session loading operate independently without ensuring both use the same user record. An authenticated Editor can create a username collision with an Administrator account and obtain administrative privileges by logging in with their own password while the session loads the Administrator's account data.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.