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TI-2026-05795 Aliases CVE-2026-6608GHSA-f3q6-69f3-vwch

lm-sys fastchat Arena Side-by-Side View add_text control flow

Priority HIGH 70CWE-670Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00308 23rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
lm-sysfastchat0.2.0; 0.2.1; 0.2.2; 0.2.3; 0.2.4; 0.2.5; 0.2.6; 0.2.7; 0.2.8; 0.2.9; 0.2.10; 0.2.11; 0.2.12; 0.2.13; 0.2.14; 0.2.15; 0.2.16; 0.2.17; 0.2.18; 0.2.19; 0.2.20; 0.2.21; 0.2.22; 0.2.23; 0.2.24; 0.2.25; 0.2.26; 0.2.27; 0.2.28; 0.2.29; 0.2.30; 0.2.31; 0.2.32; 0.2.33; 0.2.34; 0.2.35; 0.2.36—No fix listedCNA
—fschat (PyPI)up to 0.2.36—No fix listedGHSA-f3q6-69f3-vwch
  • fastchat Vendorlm-sys Affected 0.2.0; 0.2.1; 0.2.2; 0.2.3; 0.2.4; 0.2.5; 0.2.6; 0.2.7; 0.2.8; 0.2.9; 0.2.10; 0.2.11; 0.2.12; 0.2.13; 0.2.14; 0.2.15; 0.2.16; 0.2.17; 0.2.18; 0.2.19; 0.2.20; 0.2.21; 0.2.22; 0.2.23; 0.2.24; 0.2.25; 0.2.26; 0.2.27; 0.2.28; 0.2.29; 0.2.30; 0.2.31; 0.2.32; 0.2.33; 0.2.34; 0.2.35; 0.2.36 Fixed in — No fix listed CNA
  • fschat (PyPI) Vendor— Affected up to 0.2.36 Fixed in — No fix listed GHSA-f3q6-69f3-vwch

CPE names CNA · 1

CPEVersionsRoleVendor
cpe:2.3:a:lm-sys:fastchat:*:*:*:*:*:*:*:*——lm-sys
  • cpe:2.3:a:lm-sys:fastchat:*:*:*:*:*:*:*:* Versions — — ·lm-sys

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-6608
  2. 2026-10-03 Alias added: GHSA-f3q6-69f3-vwch

References

Exploit 1

Advisory 1

Other 3

  • TI-2024-09320 SSRF in POST /worker_generate_stream API endpoint in lm-sys/fastchat CVSS 3.0CRITICAL 9.3
  • TI-2024-11482 Server Side Request Forgery in lm-sys/fastchat CVSS 3.0HIGH 7.5
  • TI-2024-10750 Server-Side Request Forgery in lm-sys/fastchat CVSS 3.0HIGH 7.5
  • TI-2024-10115 Denial of Service in lm-sys/fastchat CVSS 3.0HIGH 7.5
  • TI-2024-10111 Denial of Service (DoS) via Multipart Boundary in lm-sys/fastchat CVSS 3.0HIGH 7.5
  • TI-2026-05794 lm-sys fastchat Worker API Endpoint api_generate resource consumption CVSS 4.0MEDIUM 6.9
See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences