CVE-2025-52902Public exploitNetwork attack vector

Session theft via unsanitized Markdown preview

Published Jun 26, 2025 · Updated Jun 26, 2025

Stored XSS in File Browser before 2.33.7 allows remote authenticated users to execute JavaScript in another user's browser via a Markdown file. The Markdown preview in Editor.vue passes uploaded Markdown through marked and inserts the resulting HTML without sanitization, allowing event handlers to run. A user in the same scope must open the malicious file; the script can steal that user's session token or inherit administrator privileges.

CVSS severity7.6
High
EPSS probability0.30%
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 File Browser before 2.33.7 allows remote authenticated users to execute JavaScript in another user's browser via a Markdown file. The Markdown preview in Editor.vue passes uploaded Markdown through marked and inserts the resulting HTML without sanitization, allowing event handlers to run. A user in the same scope must open the malicious file; the script can steal that user's session token or inherit administrator privileges.

The record

CVE
CVE-2025-52902
Published
Jun 26, 2025
Updated
Jun 26, 2025
Vendor
File Browser
Product
File Browser
Classifications
CWE-80, CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 26, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 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=< 2.33.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

File Browser · File Browserversion=< 2.33.7

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
7.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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