PT-2025-40903 · Unknown · Sillytavern

Atom1Cbyte · Published 2025-09-13 · Updated 2025-10-08 · CVE-2025-59159

Positive Technologies (AI Summary)

CVSS v3.1

10

Critical

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions SillyTavern versions prior to 1.13.4

Description SillyTavern is a locally installed user interface for interacting with large language models, image generation engines, and text-to-speech models. The web user interface, in versions prior to 1.13.4, is susceptible to DNS rebinding. This allows attackers to perform actions such as installing malicious extensions, reading chats, and injecting arbitrary HTML for phishing attacks. The issue enables full remote code execution (RCE)-like control over a user’s SillyTavern instance. Attackers can exploit this by hosting a malicious HTML file and tricking a user’s browser into resolving a specific DNS address. The vulnerability was addressed in version 1.13.4 by introducing a server configuration setting that validates host names in inbound HTTP requests, using a whitelist of allowed hosts. This setting is controlled by hostWhitelist.enabled in the config.yaml file or the SILLYTAVERN HOSTWHITELIST ENABLED environment variable.

Recommendations Update to SillyTavern version 1.13.4 or later. Enable the hostWhitelist.enabled setting in the config.yaml file or set the SILLYTAVERN HOSTWHITELIST ENABLED environment variable to validate host names in inbound HTTP requests.

Exploit

Fix

RCE

Origin Validation Error

Weakness Enumeration

CWE-346

CWE-940

Related Identifiers

BDU:2026-05186

CVE-2025-59159

GHSA-7CXJ-W27X-X78Q

Affected Products

Sillytavern

References · 19

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/59xxx/CVE-2025-59159.json · Exploit
• https://osv.dev/vulnerability/CVE-2025-59159 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-05186 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-59159 · Security Note
• https://osv.dev/vulnerability/GHSA-7cxj-w27x-x78q · Vendor Advisory
• https://github.com/SillyTavern/SillyTavern · Note
• https://github.com/SillyTavern/SillyTavern/releases/tag/1.13.4 · Note
• https://github.com/SillyTavern/SillyTavern/commit/d134abd50e4a416e3b81233242583b0a23f38320 · Note
• https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-7cxj-w27x-x78q · Note
• https://twitter.com/CCBalert/status/1975579005722993012 · Twitter Post
• https://t.me/cveNotify/137524 · Telegram Post
• https://twitter.com/0dayPublishing/status/1975228068189933595 · Twitter Post
• https://docs.sillytavern.app/administration/config-yaml/#host-whitelisting · Note
• https://docs.sillytavern.app/administration/#security-checklist · Note
• https://t.me/pentestingnews/69195 · Telegram Post