CVE-2025-50183Public exploitNetwork attack vector

Stored XSS via extension-blind Markdown preview

Published Jun 19, 2025 · Updated Jun 23, 2025

Stored XSS in OpenList before 4.0.0-rc.4 allows remote attackers to run JavaScript when a user previews a crafted Python file. The MdPreview component passed fetched file content to the Markdown renderer without the file extension, so Python text containing script tags was handled as renderable HTML. An attacker must place the file in accessible storage and persuade a user to open its rendered preview; the script then runs in the browser context and can read browser-accessible data.

CVSS severity6.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in OpenList before 4.0.0-rc.4 allows remote attackers to run JavaScript when a user previews a crafted Python file. The MdPreview component passed fetched file content to the Markdown renderer without the file extension, so Python text containing script tags was handled as renderable HTML. An attacker must place the file in accessible storage and persuade a user to open its rendered preview; the script then runs in the browser context and can read browser-accessible data.

The record

CVE
CVE-2025-50183
Published
Jun 19, 2025
Updated
Jun 23, 2025
Vendor
OpenList Team
Product
OpenList
Classifications
CWE-79, T1059.007, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.0.0-rc.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenList Team · OpenListversion=< 4.0.0-rc.4

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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