CVE-2023-33962

JStachio XSS vulnerability: Unescaped single quotes

MEDIUM
6.1
CVSS Score
Published: May 30, 2023 at 09:42 PM UTC
Updated: June 17, 2026 at 06:02 AM UTC
1 product affected across 1 vendorJstachio

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.6%
SSVC
PoC

Description

JStachio is a type-safe Java Mustache templating engine. Prior to version 1.0.1, JStachio fails to escape single quotes `'` in HTML, allowing an attacker to inject malicious code. This vulnerability can be exploited by an attacker to execute arbitrary JavaScript code in the context of other users visiting pages that use this template engine. This can lead to various consequences, including session hijacking, defacement of web pages, theft of sensitive information, or even the propagation of malware. Version 1.0.1 contains a patch for this issue. To mitigate this vulnerability, the template engine should properly escape special characters, including single quotes. Common practice is to escape `'` as `&#39`. As a workaround, users can avoid this issue by using only double quotes `"` for HTML attributes.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.0.1
Affected range stops below 1.0.1, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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