Lucy Xss Filter
CVE-2026-23768
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V4 - API and Web Service URL allowlisting, SSRF prevention
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Credential Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS 6.1 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: Required. Public exploit/POC available. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to induce server-side HEAD requests to arbitrary URLs when the ObjectSecurityListen. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Lucy XSS Filter with ObjectSecurityListener or EmbedSecurityListener enabled is vulnerable to server-side request forgery (SSRF) via malformed embed or object tags lacking file extensions in src attributes, allowing remote attackers to trigger arbitrary HEAD requests to internal or external URLs. Public exploit code exists for this vulnerability, and no patch is currently available.
Earlier versions of this analysis (1)
lucy-xss-filter before commit 7c1de6d allows an attacker to induce server-side HEAD requests to arbitrary URLs when the ObjectSecurityListener or EmbedSecurityListener option is enabled and embed or object tags are used with a src attribute missing a file extension. [CVSS 6.1 MEDIUM]
RemediationAI
Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-918 (Server-Side Request Forgery (SSRF)). Affects Lucy-Xss-Filter. lucy-xss-filter before commit 7c1de6d allows an attacker to induce server-side HEAD requests to arbitrary URLs when the ObjectSecurityListener or EmbedSecurityListener option is enabled and embed or object tags are used with a src attribute missing a file extension.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
lucy-xss-filter before commit 7c1de6d allows an attacker to induce server-side HEAD requests to arbitrary URLs when the ObjectSecurityListener or EmbedSecurityListener option is enabled and embed or object tags are used with a src attribute missing a file extension.
Executive ViewAI
Organizations using lucy-xss-filter before commit 7c1de6d should be aware of moderate risk from CVE-2026-23768, a server-side request forgery vulnerability rated CVSS 6.1. Users could be tricked into performing unintended actions. Proof-of-concept code is publicly available. Organizations should apply vendor updates when available and monitor for exploitation.
Apply vendor patch. If patching is delayed: implement egress filtering, block metadata endpoints.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Server-Side Request Forgery exploits applications that fetch remote resources based on user-supplied URLs.
Exploit-DB