EUVD-2026-55793
GHSA-8vfw-vh7q-p649
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L/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
High-privilege auth and victim click required; scope changes to victim browser enabling cookie theft, so S:C with C:L/I:L and no server-side availability impact.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
Lifecycle Timeline
1DescriptionCVE.org
Typemill CMS version 2.x contains a persistent cross-site scripting vulnerability in the Markdown parser extension that allows authenticated users with theme-configuration access to inject malicious JavaScript URIs by supplying unsanitized href values in Markdown links. Attackers can craft Markdown links using the javascript: scheme through ParsedownExtension.php or TwigMarkdownExtension.php, storing a persistent payload that executes in the browser of every visitor who clicks the link, enabling session cookie theft, authenticated request forgery, and credential harvesting.
AnalysisAI
Persistent XSS in Typemill CMS 2.x enables authenticated users holding theme-configuration access to store malicious JavaScript URI payloads via Markdown link syntax, which execute in victim browsers upon link click. The vulnerability exists in ParsedownExtension.php and TwigMarkdownExtension.php, where href values in Markdown links are rendered into HTML anchor tags without filtering the javascript: URI scheme, resulting in stored payloads that persist across all page loads. Successful exploitation delivers session cookie theft, authenticated request forgery, and credential harvesting against every visitor who clicks an injected link. No public exploit code or CISA KEV listing has been identified at time of analysis.
Technical ContextAI
Typemill is a PHP flat-file CMS that delegates content rendering to Markdown parser extensions built atop the Parsedown library. Two extension files - ParsedownExtension.php and TwigMarkdownExtension.php - process Markdown link syntax ([text](href)) and emit HTML anchor tags. The root cause is CWE-79 (Improper Neutralization of Input During Web Page Generation): neither extension validates the URI scheme of href values before embedding them in output HTML, allowing the javascript: scheme to survive into rendered page markup as a stored payload. Because the payload is stored server-side in flat files rather than reflected in a single request, it executes in every victim browser that encounters and clicks the injected anchor, multiplying impact beyond the moment of injection. Affected product per CPE: cpe:2.3:a:typemill:typemill:*:*:*:*:*:*:*:* - all 2.x versions prior to 2.23.0.
RemediationAI
Upgrade Typemill CMS to version 2.23.0 or later, which contains the vendor-released patch resolving the javascript: URI injection in Markdown link processing; the release is available at https://github.com/typemill/typemill/releases/tag/2.23.0. If immediate upgrade is not feasible, restrict theme-configuration access exclusively to fully trusted, vetted administrative accounts - since the vulnerability is gated on that privilege level, eliminating untrusted access to that role eliminates the attack path. As an additional compensating control, deploying a Content Security Policy header with a restrictive default-src or script-src directive (e.g., script-src 'self') can cause modern browsers to block javascript: URI execution, though this does not remove the stored payload and may interfere with legitimate site JavaScript. Administrators should audit existing Markdown content for links containing the javascript: scheme as part of post-patch remediation, as prior exploitation would leave persistent payloads in place until removed or overwritten.
In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it
sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not
(1) boardData102.php, (2) boardData103.php, (3) boardDataJP.php, (4) boardDataNA.php, and (5) boardDataWW.php in Netgear
The '/common/download_agent_installer.php' script in the Quest KACE System Management Appliance 8.0.318 is accessible by
ProjectSend versions prior to r1720 are affected by an improper authentication vulnerability. Rated critical severity (C
Roundcube Webmail contains a critical PHP object deserialization vulnerability (CVE-2025-49113, CVSS 9.9) that allows au
Util/PHP/eval-stdin.php in PHPUnit before 4.8.28 and 5.x before 5.6.3 allows remote attackers to execute arbitrary PHP c
Palo Alto Networks PAN-OS management web interface contains an authentication bypass allowing unauthenticated attackers
Nagios XI version xi-5.7.5 is affected by OS command injection. Rated high severity (CVSS 8.8), this vulnerability is re
Nagios XI version xi-5.7.5 is affected by OS command injection. Rated high severity (CVSS 8.8), this vulnerability is re
The get_referers function in /opt/ws/bin/sblistpack in Sophos Web Appliance before 3.7.9.1 and 3.8 before 3.8.1.1 allows
The Backup Migration plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 1
Same weakness CWE-79 – Cross-site Scripting (XSS)
View allShare
External POC / Exploit Code
Leaving vuln.today