Vulnerability · Published Jan 16, 2026 · Assigned by GitHub_M

CVE-2026-23742Skipper arbitrary code execution through lua filters

High 8.8

In plain English

A high-severity code injection in skipper from zalando. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.5%top 56.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Skipper is an HTTP router and reverse proxy for service composition. The default skipper configuration before 0.23.0 was -lua-sources=inline,file. The problem starts if untrusted users can create lua filters, because of -lua-sources=inline , for example through a Kubernetes Ingress resource. The configuration inline allows these user to create a script that is able to read the filesystem accessible to the skipper process and if the user has access to read the logs, they an read skipper secrets. This vulnerability is fixed in 0.23.0.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/zalando/skipper	0.23.0	GHSA-cc8m-98fm-rc9g
Go	github.com/zalando/skipper	0.23.0	GO-2026-4327

Affected products (as reported)

Vendor	Product	Versions
zalando	skipper	< 0.23.0

Weakness: CWE-94, CWE-250, CWE-522 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/zalando/skipper/security/advisories/GHSA-cc8m-98fm-rc9g x_refsource_CONFIRM
https://github.com/zalando/skipper/commit/0b52894570773b29e2f3c571b94b4211ef8fa714 x_refsource_MISC
https://github.com/zalando/skipper/releases/tag/v0.23.0 x_refsource_MISC