CVE-2026-73628: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in s9y Serendipity
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.
AI Analysis
Technical Summary
The vulnerability in Serendipity affects versions >=2.3.5 and <=2.6.0 in the search clean-URL route (/search/<term>). The sanitization pipeline in include/functions_routing.inc.php's serveSearch() function applies urldecode() after HTML encoding, which causes URL-encoded HTML payloads to survive strip_tags() and htmlspecialchars(). These payloads are then decoded back into executable HTML/JavaScript in the rendered page, enabling reflected cross-site scripting attacks. The issue is resolved in version 2.6.1.
Potential Impact
An attacker can craft a malicious search URL that, when visited by a victim, executes arbitrary JavaScript in the victim's browser. This can lead to session hijacking, defacement, or other client-side attacks depending on the victim's context. The vulnerability requires user interaction (clicking a crafted link) and has a medium severity score (CVSS 5.3). No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade Serendipity to version 2.6.1 or later, where this vulnerability is fixed. No other official remediation or temporary fixes are documented. Patch status is confirmed by the vendor's fixed version 2.6.1.
CVE-2026-73628: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in s9y Serendipity
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.
CVSS v4.0
Score 5.3medium
Affected software
pkg:github/s9y/SerendipityRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Serendipity affects versions >=2.3.5 and <=2.6.0 in the search clean-URL route (/search/<term>). The sanitization pipeline in include/functions_routing.inc.php's serveSearch() function applies urldecode() after HTML encoding, which causes URL-encoded HTML payloads to survive strip_tags() and htmlspecialchars(). These payloads are then decoded back into executable HTML/JavaScript in the rendered page, enabling reflected cross-site scripting attacks. The issue is resolved in version 2.6.1.
Potential Impact
An attacker can craft a malicious search URL that, when visited by a victim, executes arbitrary JavaScript in the victim's browser. This can lead to session hijacking, defacement, or other client-side attacks depending on the victim's context. The vulnerability requires user interaction (clicking a crafted link) and has a medium severity score (CVSS 5.3). No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade Serendipity to version 2.6.1 or later, where this vulnerability is fixed. No other official remediation or temporary fixes are documented. Patch status is confirmed by the vendor's fixed version 2.6.1.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-13T11:17:25.160Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7dbdfdbf8831d5393226d1
Added to database: 08/13/2026, 12:52:13 UTC
Last enriched: 08/13/2026, 12:57:42 UTC
Last updated: 08/13/2026, 21:43:06 UTC
Views: 8
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