4.3

CVE-2026-54247: Skipper: Unbounded Request Body Read in Admission Webhook Causes Memory Exhaustion DoS

Deferred
AliasesGHSA-cwxq-rc9x-2jvvGO-2026-6015
Published 14-09-2026Last modified 16-09-2026

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.

Priority
Routine

Not severe (CVSS 4.3, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1

Timeline

  1. 14-09-2026
    PublishedVulnerability first disclosed.
  2. 16-09-2026
    Last 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

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

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

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

2 vendors · 2 products

References

5 links