6.1
MEDIUM CVSS 3.1
CVE-2026-73628
Serendipity 2.3.5 Reflected XSS via search clean-URL route
Description

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.

INFO

Published Date :

Aug. 13, 2026, 12:17 p.m.

Last Modified :

Aug. 13, 2026, 12:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-73628 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 S9y serendipity
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update Serendipity to version 2.6.1 or later to fix a reflected cross-site scripting vulnerability.
  • Update Serendipity to version 2.6.1 or later.
  • Apply the provided patch if updating is not possible.
  • Sanitize user input for search queries.
  • Validate URLs before processing them.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-73628.

URL Resource
https://github.com/s9y/Serendipity/security/advisories/GHSA-6c2x-mjmq-vx4q
https://www.vulncheck.com/advisories/serendipity-reflected-xss-via-search-clean-url-route
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-73628 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-73628 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-73628 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-73628 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 13, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 's9y', 'product': 'Serendipity', 'versions': [{'status': 'unaffected', 'version': '0', 'lessThan': '2.3.5', 'versionType': 'semver'}], 'defaultStatus': 'affected'}]
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added Reference https://github.com/s9y/Serendipity/security/advisories/GHSA-6c2x-mjmq-vx4q
    Added Reference https://www.vulncheck.com/advisories/serendipity-reflected-xss-via-search-clean-url-route
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.