5.5
MEDIUM CVSS 4.0
CVE-2026-6607
lm-sys fastchat Worker API Endpoint api_generate resource consumption
Description

A security vulnerability has been detected in lm-sys fastchat up to 0.2.36. This issue affects the function api_generate of the component Worker API Endpoint. The manipulation leads to resource consumption. The attack can be initiated remotely. The exploit has been disclosed publicly and may be used. The identifier of the patch is c9e84b89c91d45191dc24466888de526fa04cf33. It is suggested to install a patch to address this issue. Commit ff66426 patched this issue in api_generate of base_model_worker.py and did miss other entry points.

INFO

Published Date :

April 20, 2026, 5:16 a.m.

Last Modified :

April 20, 2026, 5:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-6607 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 the latest version to prevent resource consumption vulnerabilities.
  • Apply the latest security patch from the vendor.
  • Update lm-sys fastchat to version 0.2.37 or later.
  • Review and patch all affected entry points.
  • Monitor resource consumption after patching.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-6607 is associated with the following CWEs:

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-2026-6607 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-6607 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 security vulnerability has been detected in lm-sys fastchat up to 0.2.36. This issue affects the function api_generate of the component Worker API Endpoint. The manipulation leads to resource consumption. The attack can be initiated remotely. The exploit has been disclosed publicly and may be used. The identifier of the patch is c9e84b89c91d45191dc24466888de526fa04cf33. It is suggested to install a patch to address this issue. Commit ff66426 patched this issue in api_generate of base_model_worker.py and did miss other entry points.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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:N/A:L
    Added CVSS V2 (AV:N/AC:L/Au:N/C:N/I:N/A:P)
    Added CWE CWE-404
    Added CWE CWE-400
    Added Reference https://gist.github.com/YLChen-007/87216a2d97a882d619e11dc67cd473b5
    Added Reference https://github.com/lm-sys/FastChat/
    Added Reference https://github.com/lm-sys/FastChat/commit/c9e84b89c91d45191dc24466888de526fa04cf33
    Added Reference https://github.com/lm-sys/FastChat/issues/3833
    Added Reference https://github.com/lm-sys/FastChat/pull/3835
    Added Reference https://vuldb.com/submit/792227
    Added Reference https://vuldb.com/vuln/358242
    Added Reference https://vuldb.com/vuln/358242/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.