CVE-2026-67351
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk30th percentile - higher than 30% of all known CVEs
Summary
Serendipity before version 2.6.1 has an authentication context confusion vulnerability where password validation and session loading operate independently. 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.
Risk Assessment
An attacker with Editor role can escalate privileges to administrative level, potentially leading to full CMS compromise and data breach.
Recommendation
Immediately upgrade Serendipity to version 2.6.1 or later, which includes a fix for this vulnerability.
Other vulnerabilities in Serendipity
See all- CVE-2026-73628Medium
Serendipity versions >= 2.3.5 and <= 2.6.0 contain a reflected cross-site scripting vulnerability in the search clean-URL route (/search/<term>). In include/functions_routing.inc.php serveSearch(), the sanitisation pipeline runs urldecode() after HTML-encoding, so a single URL-encoded HTML payload survives strip_tags() and htmlspecialchars() and is then decoded back into live HTML in the page. A crafted search link can execute arbitrary JavaScript in the victim's browser. Fixed in 2.6.1.
- CVE-2017-8101High
There is a CSRF vulnerability in Serendipity version 2.0.5 that allows attackers to install any themes via a GET request.
- CVE-2017-5609High
SQL injection vulnerability in include/functions_entries.inc.php in Serendipity 2.0.5 allows remote authenticated users to execute arbitrary SQL commands via the cat parameter.
- CVE-2017-5476High
Serendipity version 2.0.5 allows CSRF attacks that enable the installation of an event plugin or a sidebar plugin.
- CVE-2016-9752High
In Serendipity before 2.0.5, an attacker can bypass SSRF protection by using a malformed IP address (e.g., http://127.1) or a 30x (aka Redirection) HTTP status code.
- CVE-2026-73629High
Serendipity before 2.6.0 contains a server-side request forgery vulnerability in the serendipity_url_allowed() filter that fails to block hex-encoded IPv4 addresses, IPv6 literals, and link-local ranges. Authenticated users with adminImagesAdd permission can bypass the filter using alternate address formats to request internal services and retrieve response bodies through the public uploads directory.
- CVE-2026-67350Medium
Serendipity before version 2.6.1 contains an open redirect vulnerability in exit.php. Unauthenticated attackers can redirect users to arbitrary external sites by supplying a malicious Base64-encoded url parameter when the Track Exits plugin is configured with commentredirection set to s9y.
Original NVD description (English source)
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.