5.5
MEDIUM CVSS 4.0
CVE-2026-6608
lm-sys fastchat Arena Side-by-Side View add_text control flow
Description

A vulnerability was detected in lm-sys fastchat up to 0.2.36. Impacted is the function add_text of the component Arena Side-by-Side View Handler. The manipulation results in incorrect control flow. The attack can be launched remotely. The exploit is now public and may be used. The root cause was fixed in commit 34eca62 for gradio_block_arena_named.py, but three other files were missed.

INFO

Published Date :

April 20, 2026, 6:16 a.m.

Last Modified :

April 20, 2026, 6:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-6608 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 MEDIUM [email protected]
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM [email protected]
Solution
Update lm-sys fastchat to a patched version to fix incorrect control flow.
  • Update lm-sys fastchat to version 0.2.37 or later.
  • Apply the fix from commit 34eca62 and other relevant commits.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-6608.

URL Resource
https://gist.github.com/YLChen-007/e45039d23e698222d887ee09735d9d36
https://github.com/lm-sys/FastChat/
https://github.com/lm-sys/FastChat/issues/3834
https://vuldb.com/submit/792228
https://vuldb.com/vuln/358243
https://vuldb.com/vuln/358243/cti
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-6608 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-6608 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-6608 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-6608 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 20, 2026

    Action Type Old Value New Value
    Added Description A vulnerability was detected in lm-sys fastchat up to 0.2.36. Impacted is the function add_text of the component Arena Side-by-Side View Handler. The manipulation results in incorrect control flow. The attack can be launched remotely. The exploit is now public and may be used. The root cause was fixed in commit 34eca62 for gradio_block_arena_named.py, but three other files were missed.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
    Added CVSS V2 (AV:N/AC:L/Au:N/C:N/I:P/A:N)
    Added CWE CWE-670
    Added Reference https://gist.github.com/YLChen-007/e45039d23e698222d887ee09735d9d36
    Added Reference https://github.com/lm-sys/FastChat/
    Added Reference https://github.com/lm-sys/FastChat/issues/3834
    Added Reference https://vuldb.com/submit/792228
    Added Reference https://vuldb.com/vuln/358243
    Added Reference https://vuldb.com/vuln/358243/cti
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.