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4 vulnerabilities found for fastchat by lm-sys
CVE-2026-85695 (GCVE-0-2026-85695)
Vulnerability from cvelistv5 – Published: 2026-09-04 14:32 – Updated: 2026-10-01 15:21
VLAI
EPSS
VEX
Title
FastChat Unauthenticated Worker Registration SSRF and Model Spoofing
Summary
FastChat contains an authentication bypass vulnerability in the /register_worker endpoint that allows unauthenticated attackers to register arbitrary worker addresses and perform server-side request forgery. Attackers can register malicious workers under victim model names to intercept user prompts, images, and responses, or probe internal network ports across the worker mesh.
Severity
9.4 (Critical)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-04 15:04 UTC
CWE
- CWE-306 - Missing Authentication for Critical Function
Assigner
VulnCheck
CNA
References
4 references
| URL | Tags |
|---|---|
| https://github.com/lm-sys/FastChat/issues/3886 | issue-tracking |
| https://github.com/lm-sys/FastChat | product |
| https://github.com/lm-sys/FastChat/blob/v0.2.36/f… | technical-description |
| https://www.vulncheck.com/advisories/fastchat-una… | third-party-advisory |
Impacted products
Date Public
2026-06-12 00:00
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CVE-2026-6608 (GCVE-0-2026-6608)
Vulnerability from cvelistv5 – Published: 2026-04-20 05:15 – Updated: 2026-04-20 14:57
VLAI
EPSS
VEX
Title
lm-sys fastchat Arena Side-by-Side View add_text control flow
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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-20 14:57 UTC
CWE
- CWE-670 - Incorrect Control Flow
Assigner
VulDB
CNA
References
6 references
| URL | Tags |
|---|---|
| https://vuldb.com/vuln/358243 | vdb-entrytechnical-description |
| https://vuldb.com/vuln/358243/cti | signaturepermissions-required |
| https://vuldb.com/submit/792228 | third-party-advisory |
| https://github.com/lm-sys/FastChat/issues/3834 | issue-tracking |
| https://gist.github.com/YLChen-007/e45039d23e6982… | exploit |
| https://github.com/lm-sys/FastChat/ | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| lm-sys | fastchat |
Affected:
0.2.0
Affected: 0.2.1 Affected: 0.2.2 Affected: 0.2.3 Affected: 0.2.4 Affected: 0.2.5 Affected: 0.2.6 Affected: 0.2.7 Affected: 0.2.8 Affected: 0.2.9 Affected: 0.2.10 Affected: 0.2.11 Affected: 0.2.12 Affected: 0.2.13 Affected: 0.2.14 Affected: 0.2.15 Affected: 0.2.16 Affected: 0.2.17 Affected: 0.2.18 Affected: 0.2.19 Affected: 0.2.20 Affected: 0.2.21 Affected: 0.2.22 Affected: 0.2.23 Affected: 0.2.24 Affected: 0.2.25 Affected: 0.2.26 Affected: 0.2.27 Affected: 0.2.28 Affected: 0.2.29 Affected: 0.2.30 Affected: 0.2.31 Affected: 0.2.32 Affected: 0.2.33 Affected: 0.2.34 Affected: 0.2.35 Affected: 0.2.36 cpe:2.3:a:lm-sys:fastchat:*:*:*:*:*:*:*:* |
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CVE-2026-6607 (GCVE-0-2026-6607)
Vulnerability from cvelistv5 – Published: 2026-04-20 05:00 – Updated: 2026-04-20 11:37 X_Open Source
VLAI
EPSS
VEX
Title
lm-sys fastchat Worker API Endpoint api_generate resource consumption
Summary
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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-20 11:36 UTC
Assigner
VulDB
CNA
References
8 references
| URL | Tags |
|---|---|
| https://vuldb.com/vuln/358242 | vdb-entrytechnical-description |
| https://vuldb.com/vuln/358242/cti | signaturepermissions-required |
| https://vuldb.com/submit/792227 | third-party-advisory |
| https://github.com/lm-sys/FastChat/issues/3833 | issue-tracking |
| https://github.com/lm-sys/FastChat/pull/3835 | issue-trackingpatch |
| https://gist.github.com/YLChen-007/87216a2d97a882… | exploit |
| https://github.com/lm-sys/FastChat/commit/c9e84b8… | patch |
| https://github.com/lm-sys/FastChat/ | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| lm-sys | fastchat |
Affected:
0.2.0
Affected: 0.2.1 Affected: 0.2.2 Affected: 0.2.3 Affected: 0.2.4 Affected: 0.2.5 Affected: 0.2.6 Affected: 0.2.7 Affected: 0.2.8 Affected: 0.2.9 Affected: 0.2.10 Affected: 0.2.11 Affected: 0.2.12 Affected: 0.2.13 Affected: 0.2.14 Affected: 0.2.15 Affected: 0.2.16 Affected: 0.2.17 Affected: 0.2.18 Affected: 0.2.19 Affected: 0.2.20 Affected: 0.2.21 Affected: 0.2.22 Affected: 0.2.23 Affected: 0.2.24 Affected: 0.2.25 Affected: 0.2.26 Affected: 0.2.27 Affected: 0.2.28 Affected: 0.2.29 Affected: 0.2.30 Affected: 0.2.31 Affected: 0.2.32 Affected: 0.2.33 Affected: 0.2.34 Affected: 0.2.35 Affected: 0.2.36 cpe:2.3:a:lm-sys:fastchat:*:*:*:*:*:*:*:* |
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CVE-2025-3677 (GCVE-0-2025-3677)
Vulnerability from cvelistv5 – Published: 2025-04-16 08:31 – Updated: 2025-04-21 11:28
VLAI
EPSS
VEX
Title
lm-sys fastchat apply_delta.py apply_delta_low_cpu_mem deserialization
Summary
A vulnerability classified as critical was found in lm-sys fastchat up to 0.2.36. This vulnerability affects the function split_files/apply_delta_low_cpu_mem of the file fastchat/model/apply_delta.py. The manipulation leads to deserialization. An attack has to be approached locally.
Severity
5.3 (Medium)
5.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-04-16 19:30 UTC
Assigner
VulDB
CNA
References
4 references
| URL | Tags |
|---|---|
| https://vuldb.com/?id.304966 | vdb-entrytechnical-description |
| https://vuldb.com/?ctiid.304966 | signaturepermissions-required |
| https://vuldb.com/?submit.552755 | third-party-advisory |
| https://github.com/lm-sys/FastChat/issues/3713 | issue-tracking |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| lm-sys | fastchat |
Affected:
0.2.0
Affected: 0.2.1 Affected: 0.2.2 Affected: 0.2.3 Affected: 0.2.4 Affected: 0.2.5 Affected: 0.2.6 Affected: 0.2.7 Affected: 0.2.8 Affected: 0.2.9 Affected: 0.2.10 Affected: 0.2.11 Affected: 0.2.12 Affected: 0.2.13 Affected: 0.2.14 Affected: 0.2.15 Affected: 0.2.16 Affected: 0.2.17 Affected: 0.2.18 Affected: 0.2.19 Affected: 0.2.20 Affected: 0.2.21 Affected: 0.2.22 Affected: 0.2.23 Affected: 0.2.24 Affected: 0.2.25 Affected: 0.2.26 Affected: 0.2.27 Affected: 0.2.28 Affected: 0.2.29 Affected: 0.2.30 Affected: 0.2.31 Affected: 0.2.32 Affected: 0.2.33 Affected: 0.2.34 Affected: 0.2.35 Affected: 0.2.36 |
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