CVE-2026-44651 SillyTavern: Reflected XSS vulnerability in the CORS proxy middleware
An attacker can execute arbitrary scripts in the victim's browser via reflected XSS in the CORS proxy error handling of SillyTavern.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44651?
CVE-2026-44651 is a medium-severity cross-site scripting vulnerability in SillyTavern, published on 29 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
SillyTavern is a locally installed user interface that allows users to interact with text generation large language models, image generation engines, and text-to-speech voice models. Prior to 1.18.0, when fetch(url) throws, the code sends: res.status(500).send('Error occurred while trying to proxy to: ' + url + ' ' + error). The url value is attacker-controlled (req.params.url) and is not HTML-escaped before rendering. This vulnerability is fixed in 1.18.0.
Weakness: CWE-79
Which versions are affected by CVE-2026-44651?
2 open source packages ship an affected version, including sillytavern.
| Package | Affected | Fixed in |
|---|---|---|
sillytavern npm | All versions | 1.18.0 |
sillytavern npm | All versions | 1.18.0 |
How do I fix CVE-2026-44651?
Upgrade sillytavern to 1.18.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-44651 being exploited?
There is no known exploitation of CVE-2026-44651 in the wild and no public exploit code.
Sources
Also known as GHSA-xc4x-2452-5gc9.