CVE-2026-54247: Skipper: Unbounded Request Body Read in Admission Webhook Causes Memory Exhaustion DoS
Vulnerability summary
CVE-2026-54247 is a medium (CVSS 4.3) vulnerability in zalando skipper. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 22.5% of scored vulnerabilities.
Not severe (CVSS 4.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 14-09-2026PublishedVulnerability first disclosed.
- 16-09-2026Last modifiedVulnerability information updated.
Description
Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.26.22, Handler in dataclients/kubernetes/admission/admission.go passes the body of requests to the Kubernetes admission endpoint at :9443/admission directly to io.ReadAll(r.Body) without a size limit. An attacker with in-cluster network access and a valid Kubernetes client certificate can send a very large body that causes unbounded memory allocation and an out-of-memory termination of the Skipper process. The disruption is limited to Ingress and RouteGroup admission rather than pod creation or unrelated admission controllers, and Kubernetes normally restarts the process. This issue is fixed in version 0.26.22.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · GoEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- NVDNIST4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
EPSS trend
Probability
0.30%
Chance of exploitation in the next 30 days
Percentile
23%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.30% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Github.com/zalando1 product
- skipper< 0.26.22
Zalando1 product
- skipper< 0.26.22
2 vendors · 2 products
References
5 links- github.com/zalando/skipper/pull/4053X Refsource MISC
- github.com/zalando/skipperPACKAGE