CVE-2025-55301

Local username-value modification via editable localStorage

Published Aug 25, 2025 · Updated Aug 25, 2025

Improper input validation in The Scratch Channel tsc-web-client 1 allows local users to alter a username value in browser storage. The client stores an editable username in localStorage without integrity validation, while a separate stored identifier retrieves the effective account username. Access to the same browser profile is required, and the maintainer states that changing the informational value has no account or server-side effect.

CVSS severity6.7
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in The Scratch Channel tsc-web-client 1 allows local users to alter a username value in browser storage. The client stores an editable username in localStorage without integrity validation, while a separate stored identifier retrieves the effective account username. Access to the same browser profile is required, and the maintainer states that changing the informational value has no account or server-side effect.

The record

CVE
CVE-2025-55301
Published
Aug 25, 2025
Updated
Aug 25, 2025
Vendor
The Scratch Channel
Product
tsc-web-client
Classifications
CWE-315, CWE-20
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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== 1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Scratch Channel · tsc-web-clientversion== 1

Published CVSS scores

6.7GitHub, Inc.CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-315Cleartext Storage of Sensitive Information in a Cookie
CWE-20Improper Input Validation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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