CVE-2026-107205: LMCache through 0.5.5 Missing Authentication in MP Coordinator Fleet Control API

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-07 · updated 2026-10-08
Weakness: CWE-306

Description

LMCache through 0.5.5 contains a missing authentication vulnerability in the multiprocess coordinator that allows remote unauthenticated attackers to access its HTTP fleet control API listening on all interfaces by default. Attackers can register or deregister instances via /instances, overwrite quotas via /quota endpoints, inject events via /events, and enumerate /directory/keys to disrupt caching and disclose placement metadata.

Affected products

LMCache: through 0.5.5

References

https://github.com/LMCache/LMCache
https://github.com/LMCache/LMCache/blob/v0.5.5/lmcache/v1/mp_coordinator/app.py#L238-L246
https://github.com/LMCache/LMCache/blob/v0.5.5/lmcache/v1/mp_coordinator/config.py#L71
https://github.com/LMCache/LMCache/issues/5508
https://www.vulncheck.com/advisories/lmcache-through-0.5.5-missing-authentication-in-mp-coordinator-fleet-control-api

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