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Skipper Kubernetes Admission Webhook Unbounded Request Body DoS

IdentifiersCVE-2026-54247CWE-770

CVE-2026-54247 is a denial-of-service vulnerability in Skipper's Kubernetes admission webhook handler caused by reading request bodies without an enforced size limit. A client able to reach the admission webhook and authenticate with a valid Kubernetes client certificate can submit an excessively large admission request body, leading the handler to consume unbounded memory while processing the request. The flaw affects admission control handling for Kubernetes Ingress and RouteGroup resources and can cause the Skipper process to be terminated by the operating system due to memory exhaustion.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can exhaust the memory of the Skipper process and trigger an out-of-memory termination, resulting in denial of service. This disrupts admission webhook processing for affected Kubernetes resources, preventing normal admission control decisions until the service is restarted and potentially degrading cluster operations that depend on those admission checks.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, enforce request body size limits in the admission webhook path using mechanisms such as bounded HTTP body readers. Restrict network access to the webhook to only necessary cluster components, minimize certificate issuance to trusted clients, and monitor the Skipper process for abnormal memory growth or repeated restarts indicative of attempted exploitation.

Remediation

Patch, then assume compromise.

Upgrade Skipper to version 0.26.22 or later. The vulnerable admission webhook handler should enforce strict request body size limits before reading request content into memory. Implementations should use bounded reads and configurable maximum body sizes for admission requests.

PUBLIC EXPLOITS

Exploits

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VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

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VendorProductType

ZalandoSkipperapplication

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ACTIVITY FEED

Recent activity

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0 SOURCESView more in app

No public activity observed for this vulnerability.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

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Associated malware

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Detection signatures

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Vendor-by-vendor mapping

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Social activity