# CVE-2026-44651: SillyTavern reflected XSS in CORS proxy middleware

Source: https://junglewise.ai/threats/cve-2026-44651-sillytavern-reflected-xss-in-cors-proxy-middleware  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-29. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-44651 · Severity: medium · CVSS 4 · Published 2026-05-29

SillyTavern, a user interface for interacting with text generation AI, contains a security flaw in its proxy service. An attacker can use this vulnerability to run malicious scripts in a user's browser if they are tricked into clicking a specifically crafted link. This could lead to the theft of login tokens or unauthorized manipulation of the user's session.

Technologies: [sillytavern (npm)](https://junglewise.ai/threats/technologies/sillytavern). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-44651 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-44651 being exploited in the wild.

**How severe is CVE-2026-44651?** Medium severity, with a CVSS score of 4, published 29 May 2026.

**Which products and versions are affected?** sillytavern (npm) <= 1.17.0, SEMVER:introduced=0,fixed=1.18.0.

**Is there a fix for CVE-2026-44651?** Yes. sillytavern (npm): upgrade to 1.18.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-44651 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-44651?** Check whether you run sillytavern (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- sillytavern (npm): upgrade to 1.18.0 or later

  ```sh
  npm install sillytavern@1.18.0
  ```


## Technical details

A reflected cross-site scripting (XSS) vulnerability exists in SillyTavern's CORS proxy middleware within `src/middleware/corsProxy.js`. The root cause is the improper neutralization of the `url` parameter in the `GET /proxy/:url(*)` route; when a fetch request fails, the application reflects the raw, unescaped URL back into a 500 error response body. An attacker can exploit this by crafting a URL containing malicious HTML/JavaScript tags. If a victim visits the crafted link, the script executes in their browser context. The issue is fixed in version 1.18.0 by ensuring user-provided URLs are no longer reflected in the response body.

## Affected products

- SillyTavern SillyTavern <= 1.17.0

## Identifiers

- CVE-2026-44651
- GHSA-xc4x-2452-5gc9

## Timeline

- 2026-05-11: disclosed
- 2026-05-12: advisory: GitHub Advisory published
- 2026-05-29: other: NVD published

## References

- [https://api.github.com/users/FORIMOC](https://api.github.com/users/FORIMOC)
- [https://github.com/FORIMOC](https://github.com/FORIMOC)
- [https://api.github.com/users/FORIMOC/gists%7B/gist_id%7D](https://api.github.com/users/FORIMOC/gists%7B/gist_id%7D)
- [https://api.github.com/users/FORIMOC/repos](https://api.github.com/users/FORIMOC/repos)
- [https://avatars.githubusercontent.com/u/73113688?v=4](https://avatars.githubusercontent.com/u/73113688?v=4)
- [https://api.github.com/users/FORIMOC/events%7B/privacy%7D](https://api.github.com/users/FORIMOC/events%7B/privacy%7D)

## Related threats

- [SillyTavern SSRF in SearXNG search proxy API](https://junglewise.ai/threats/cve-2026-46372-sillytavern-ssrf-in-searxng-search-proxy-api)
- [SillyTavern SSRF in CORS proxy middleware](https://junglewise.ai/threats/cve-2026-44652-sillytavern-ssrf-in-cors-proxy-middleware)
- [SillyTavern path traversal and directory deletion in extensions API](https://junglewise.ai/threats/cve-2026-44650-sillytavern-path-traversal-and-directory-deletion-in-extensions)
- [SillyTavern authentication bypass via SSO header injection](https://junglewise.ai/threats/cve-2026-44649-sillytavern-authentication-bypass-via-sso-header-injection)
- [SillyTavern insufficient session expiration after password change](https://junglewise.ai/threats/cve-2026-44648-sillytavern-insufficient-session-expiration-after-password-change)