CVE-2026-88008Critical· 9.1▾ MidnightTraefik is an open source HTTP reverse proxy and load balancer. From 2.11.26 until 2.11.57 and 3.7.13, Traefik forwards a client-supplied Connection header requesting Upgrade, the Upgrade: h2c token, and HTTP2-Settings to a shared backen…
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 50.1 · likelihood 0.1 · exploitation 0
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Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 11.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.4%
Last analysed / modified upstream
7 → 9.1
high → critical
Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.26 until 2.11.57 and 3.7.13, Traefik forwards a client-supplied Connection header requesting Upgrade, the Upgrade: h2c token, and HTTP2-Settings to a shared backend. If the backend accepts h2c and returns 101 Switching Protocols, Traefik enters a raw tunnel and no longer applies routers, BasicAuth, ForwardAuth, IPAllowList, RateLimit, access logging, metrics, or tracing to later HTTP/2 requests, allowing an unauthenticated request through an unprotected route to reach protected paths on the same backend. This issue is fixed in 2.11.57 and 3.7.13.
traefik >= 2.11.26, < 2.11.57traefik >= 3.4.2, < 3.7.13Upgrade past the affected range:
traefik 3.7.13Affected packages:
github.com/traefik/traefik/v3 >= 3.4.2, < 3.7.13github.com/traefik/traefik/v2 >= 2.11.26, < 2.11.57Patched in:
github.com/traefik/traefik/v3 3.7.13github.com/traefik/traefik/v2 2.11.57Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
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