CVE-2026-100674 stoatchat before 0.15.5 Username Validation Bypass via Unicode Sanitization
Attackers can bypass username validation rules in stoatchat to create reserved-name lookalikes and embed forbidden characters by exploiting Unicode sanitization flaws.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-100674?
CVE-2026-100674 is a medium-severity vulnerability in stoatchat, published on 26 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-180
Which versions are affected by CVE-2026-100674?
How do I fix CVE-2026-100674?
No fix has been published for CVE-2026-100674 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-100674 being exploited?
There is no known exploitation of CVE-2026-100674 in the wild and no public exploit code.
Sources
Also known as GHSA-j26j-r3xm-q4wf, GHSA-qcwh-c934-wrv5.