CVE-2026-100674

stoatchat before 0.15.5 Username Validation Bypass via Unicode Sanitization

Published Sep 26, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
stoatchat before 0.15.5 fails to revalidate usernames after Unicode sanitization, allowing attackers to create usernames with forbidden characters by submitting Unicode letters that transform into rejected characters. Attackers can bypass character allowlists and length limits to create reserved-name lookalikes, embed special characters, and exceed the 32-character storage limit.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Stoatchat
Stoatchat stoatchat
Vendors & Products Stoatchat
Stoatchat stoatchat
Type Values Removed Values Added
Description stoatchat before 0.15.5 fails to revalidate usernames after Unicode sanitization, allowing attackers to create usernames with forbidden characters by submitting Unicode letters that transform into rejected characters. Attackers can bypass character allowlists and length limits to create reserved-name lookalikes, embed special characters, and exceed the 32-character storage limit.
Title stoatchat before 0.15.5 Username Validation Bypass via Unicode Sanitization
Weaknesses CWE-180
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 30, 2026, 2:58 PM
Reserved
Sep 26, 2026, 2:34 AM
Status
Deferred
Published
Sep 26, 2026, 2:16 PM
Modified
Sep 30, 2026, 3:22 PM