PT-2026-33713 · Lmsys · Fastchat

Eric-F · CVE-2026-6607 · Published 2026-04-20 · Updated 2026-07-13

Positive Technologies (AI Summary)

CVSS v4.0

5.5

Medium

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Name of the Vulnerable Software and Affected Versions lm-sys fastchat versions prior to 0.2.37

Description A flaw in the Worker API Endpoint allows remote attackers to cause resource consumption through the manipulation of the api generate() function.

Recommendations Install the patch provided in commit c9e84b89c91d45191dc24466888de526fa04cf33. As a temporary workaround, restrict access to the api generate() function to minimize the risk of resource exhaustion.

Exploit

Fix

Improper Resource Release

Resource Exhaustion

Weakness Enumeration

CWE-404

CWE-400

Related Identifiers

CVE-2026-6607

GHSA-5H65-JX66-J7P5

PYSEC-2026-2484

Affected Products

Fastchat

References · 16

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6607.json · Exploit
• 🔥 https://gist.github.com/YLChen-007/87216a2d97a882d619e11dc67cd473b5 · Exploit
• https://github.com/lm-sys/FastChat/commit/c9e84b89c91d45191dc24466888de526fa04cf33 · Patch
• https://github.com/lm-sys/FastChat/pull/3835 · Patch
• https://osv.dev/vulnerability/GHSA-5h65-jx66-j7p5 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-6607 · Security Note
• https://osv.dev/vulnerability/PYSEC-2026-2484 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-6607 · Vendor Advisory
• https://github.com/lm-sys/FastChat · Note
• https://github.com/lm-sys/FastChat/issues/3833 · Note
• https://github.com/advisories/GHSA-5h65-jx66-j7p5 · Note
• https://pypi.org/project/fschat · Note
• https://twitter.com/VulmonFeeds/status/2046136610022945097 · Twitter Post
• https://vuldb.com/submit/792227 · Note
• https://vuldb.com/vuln/358242 · Note