CVE-2025-53903Public exploitNetwork attack vector

Stored XSS via unsanitized profile fields

Published Jul 15, 2025 · Updated Jul 15, 2025

Stored XSS in /api/users.js in The Scratch Channel tsc-web-client allows remote attackers to execute scripts when a visitor opens a crafted profile. The new-user endpoint stores untrusted username and profile-image values, and profile rendering inserts them into an HTML title and image source without context-appropriate validation. Exploitation requires a visitor to open the attacker-created profile, allowing script execution in that visitor’s browser context.

CVSS severityUnavailable
Unscored
EPSS probability0.33%
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 /api/users.js in The Scratch Channel tsc-web-client allows remote attackers to execute scripts when a visitor opens a crafted profile. The new-user endpoint stores untrusted username and profile-image values, and profile rendering inserts them into an HTML title and image source without context-appropriate validation. Exploitation requires a visitor to open the attacker-created profile, allowing script execution in that visitor’s browser context.

The record

CVE
CVE-2025-53903
Published
Jul 15, 2025
Updated
Jul 15, 2025
Vendor
The Scratch Channel
Product
tsc-web-client
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 90b39eb56b27b2bac29001abb1a3cac0964b8ddb

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Scratch Channel · tsc-web-clientversion=< 90b39eb56b27b2bac29001abb1a3cac0964b8ddb

Published CVSS scores

1.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U

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')
T1059.007JavaScript/JScript

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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