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

Exp

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.

Published: 2026-01-16 Last update: 2026-02-18 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-23742 is rated Exploit Available (51.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-23742

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-23742

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-18 0.05% 0.02% -0.03%
2 2026-02-17 0.04% 0.05% +0.01%
3 2026-01-17 0.04%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23742

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2026-23742

GitHub Security Advisory for CVE-2026-23742

GHSA-cc8m-98fm-rc9g · Severity: high · Ecosystem: go — Skipper is vulnerable to arbitrary code execution through lua filters

Affected software / configurations for CVE-2026-23742

Vendor Product Version Raw CPE
zalando skipper < 0.23.0 cpe:2.3:a:zalando:skipper:*:*:*:*:*:*:*:*

References for CVE-2026-23742

cvelogic Threat Intelligence