CVE-2026-6608lm-sys fastchat Arena Side-by-Side View add_text control flow
- 6.9MediumCVSS base score
- 0.31%Exploitation in 30 daysEPSS · top 76% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
Timeline
ID reserved
By VulDB
- 1 day later
· 1 day later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P |
| VulDBCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R |
| VulDBCNA (assigner) | 3.0 | Medium5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R |
| VulDBCNA (assigner) | 2.0 | Medium5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N/E:POC/RL:ND/RC:UR |
| NVDNVD · Deferred | 4.0 | Medium5.5 | CVSS:4.0/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 |
- EPSS (exploitation in 30 days)
- 0.31% · top 76% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.
Affected products
- 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
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIfschatGHSA-f3q6-69f3-vwch (opens in a new tab)
References
References6
- VDB-358243 | lm-sys fastchat Arena Side-by-Side View add_text control flow (opens in a new tab)vdb-entrytechnical-description
- VDB-358243 | CTI Indicators (IOB, IOC, IOA) (opens in a new tab)signaturepermissions-required
- Submit #792228 | LM-Sys FastChat <= 0.2.36 Content Moderation Bypass (CWE-670) (opens in a new tab)third-party-advisory
- https://github.com/lm-sys/FastChat/issues/3834 (opens in a new tab)issue-tracking
- https://gist.github.com/YLChen-007/e45039d23e698222d887ee09735d9d36 (opens in a new tab)exploit
- https://github.com/lm-sys/FastChat/ (opens in a new tab)product
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-23780 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-f3q6-69f3-vwch (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-6608)Record last updated .