CVE-2025-51859

MEDIUM

Chaindesk <2025-05-26 - XSS

Title source: llm

Description

Stored Cross-Site Scripting (XSS) vulnerability in Chaindesk thru 2025-05-26 in its agent chat component. An attacker can achieve arbitrary client-side script execution by crafting an AI agent whose system prompt instructs the underlying Large Language Model (LLM) to embed malicious script payloads (e.g., SVG-based XSS) into its chat responses. When a user interacts with such a malicious agent or accesses a direct link to a conversation containing an XSS payload, the script executes in the user's browser. Successful exploitation can lead to the theft of sensitive information, such as JWT session tokens, potentially resulting in account hijacking.

Exploits (1)

nomisec WRITEUP
by Secsys-FDU · poc
https://github.com/Secsys-FDU/CVE-2025-51859

Scores

CVSS v3 6.5
EPSS 0.0010
EPSS Percentile 26.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Published Jul 22, 2025
Tracked Since Feb 18, 2026