CVE-2026-58172

Ocelot - IP Allow/Block List Bypass for WebSocket Upgrade Requests

CVSS 9.3 CRITICALCWE-288

Vexday Risk Score

25Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 9.3EPSS —KEV nãoPoC —Nuclei —Metasploit —Patch referenciado

Lifecycle

30 Jun 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Ocelot through 24.1.0, fixed in commit f156fd4, contains a security control bypass vulnerability that allows denied clients to circumvent IP-based access restrictions by sending WebSocket upgrade requests. The WebSocket upgrade pipeline branch configured via MapWhen in OcelotPipelineExtensions.cs omits SecurityMiddleware, causing requests from blocked IP addresses to be proxied to downstream services without enforcement of the configured allow/block list.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Affected products

ThreeMammals · Ocelot

Want to know if your infrastructure is exposed to this?

Talk to TrueHacking →

References

https://github.com/ThreeMammals/Ocelot/commit/f156fd4017ca25025fffdad8ec56c1d657dfb402 https://github.com/ThreeMammals/Ocelot/issues/2403 https://github.com/ThreeMammals/Ocelot/pull/2406 https://www.vulncheck.com/advisories/ocelot-ip-allow-block-list-bypass-for-websocket-upgrade-requests