lm-sys fastchat Worker API Endpoint api_generate resource consumption
Summary
| CVE | CVE-2026-6607 |
|---|---|
| State | PUBLISHED |
| Assigner | VulDB |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-20 05:16:16 UTC |
| Updated | 2026-04-20 05:16:16 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 5.5 MEDIUM from [email protected]
CVSS:4.0/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
Problem Types: CWE-400 | CWE-404 | CWE-400 Resource Consumption | CWE-404 Denial of Service
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 5.5 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/C... |
| 4.0 | CNA | DECLARED | 6.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P |
| 3.1 | [email protected] | Primary | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| 3.1 | CNA | DECLARED | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C |
| 3.0 | CNA | DECLARED | 5.3 | MEDIUM | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C |
| 2.0 | [email protected] | Secondary | 5 | AV:N/AC:L/Au:N/C:N/I:N/A:P | |
| 2.0 | CNA | DECLARED | 5 | AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
NoneAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
LowCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS v3.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
LowCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Lm-sys | Fastchat | affected 0.2.0 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.1 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.2 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.3 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.4 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.5 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.6 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.7 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.8 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.9 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.10 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.11 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.12 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.13 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.14 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.15 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.16 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.17 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.18 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.19 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.20 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.21 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.22 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.23 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.24 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.25 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.26 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.27 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.28 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.29 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.30 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.31 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.32 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.33 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.34 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.35 | Not specified |
| CNA | Lm-sys | Fastchat | affected 0.2.36 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/lm-sys/FastChat/pull/3835 | [email protected] | github.com | |
| vuldb.com/vuln/358242/cti | [email protected] | vuldb.com | |
| gist.github.com/YLChen-007/87216a2d97a882d619e11dc67cd473b5 | [email protected] | gist.github.com | |
| vuldb.com/vuln/358242 | [email protected] | vuldb.com | |
| github.com/lm-sys/FastChat/commit/c9e84b89c91d45191dc24466888de526fa04cf33 | [email protected] | github.com | |
| github.com/lm-sys/FastChat/issues/3833 | [email protected] | github.com | |
| github.com/lm-sys/FastChat | [email protected] | github.com | |
| vuldb.com/submit/792227 | [email protected] | vuldb.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Eric-f (VulDB User) (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-04-19T00:00:00.000Z | Advisory disclosed |
| CNA | 2026-04-19T02:00:00.000Z | VulDB entry created |
| CNA | 2026-04-19T18:04:48.000Z | VulDB entry last update |
There are currently no legacy QID mappings associated with this CVE.