stoatchat before 0.15.5 Username Validation Bypass via Unicode Sanitization
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA stoatchat (stoatchat) Fixed in 0.15.5
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
stoatchat 0.15.5
6 records Highest priority Priority HIGH 4 HIGH, 1 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-64832 stoatchat before 0.15.5 Local Filesystem Read via SVGPriority HIGH 77
- TI-2026-64833 stoatchat before 0.15.5 Account Enumeration via Error LocationPriority HIGH 70
- TI-2026-64834 stoatchat before 0.15.5 MFA Brute Force via Insufficient Rate LimitingPriority HIGH 69
Timeline
- 2026-10-02 Threatist record created from CVE-2026-100674
- 2026-10-03 Alias added: GHSA-j26j-r3xm-q4wf
References
More stoatchat vulnerabilities
- TI-2026-45152 stoatchat before 0.13.5 Unauthenticated SSRF via proxy and embed endpoints CVSS 4.0CRITICAL 9.2
- TI-2026-64832 stoatchat before 0.15.5 Local Filesystem Read via SVG CVSS 4.0HIGH 8.8
- TI-2026-51266 stoatchat before 0.15.0 Uncapped SVG Rendering Denial of Service CVSS 4.0HIGH 8.7
- TI-2026-45038 stoatchat < 0.14.0 SSRF via DNS-based IP Blocklist Bypass CVSS 4.0HIGH 7.7
- TI-2026-64833 stoatchat before 0.15.5 Account Enumeration via Error Location CVSS 4.0MEDIUM 6.9
- TI-2026-51267 stoatchat before 0.15.0 SSRF via IPv6 unspecified address bypass CVSS 4.0MEDIUM 6.9
Sources
- CVE-2026-100674 · CVE Program
- CVE-2026-100674 · NVD
- FIRST EPSS
- GHSA-j26j-r3xm-q4wf · GitHub Advisory Database · CC BY 4.0
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