Security readout for executives and security teams
Plain-English summary
Skipper versions before 0.23.0 could let a user who is allowed to define Lua filters run code inside the proxy process. In Kubernetes, this may happen through Ingress-controlled configuration. The impact can include reading files, exposing secrets through logs, and broader compromise of the Skipper runtime context.
Executive priority
Prioritize remediation for shared Kubernetes or multi-tenant environments using Skipper. The issue can turn limited configuration rights into code execution and secret exposure in the proxy context. Upgrade and permission review should be scheduled promptly.
Technical view
The vulnerable default Lua source setting before Skipper 0.23.0 included inline and file sources. If an untrusted principal can create Lua filters, inline scripts may access the filesystem available to the Skipper process and potentially expose secrets through readable logs. CVSS is 8.8, with low attack complexity and privileges required.
Likely exposure
Exposure is likely where Zalando Skipper before 0.23.0 is deployed and non-admin or tenant users can influence Lua filters, especially via Kubernetes Ingress resources. Systems without untrusted Lua filter creation are less directly exposed, but should still review configuration.
Exploitation context
No source in the provided bundle states active exploitation, and it is not listed as KEV. Exploitation requires some privilege to create or influence Lua filters. The main concern is abuse of trusted proxy configuration paths rather than unauthenticated internet scanning.
Researcher notes
The CVE maps to CWE-94, CWE-250, and CWE-522. The critical precondition is untrusted Lua filter creation with inline Lua enabled. Evidence provided identifies the fix in 0.23.0, but does not describe observed exploitation or broader affected forks.
Mitigation direction
- Upgrade Zalando Skipper to version 0.23.0 or later.
- Review vendor advisory and release notes for configuration guidance.
- Prevent untrusted users from creating or modifying Lua filters.
- Review Kubernetes Ingress permissions affecting Skipper configuration.
- Audit access to Skipper logs that may contain exposed secrets.
Validation and detection
- Inventory all Skipper deployments and record versions.
- Confirm whether any deployment is below 0.23.0.
- Check whether Lua sources allow inline scripts.
- Identify users or controllers able to define Lua filters.
- Review logs and secret exposure paths for unusual access.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-250: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-522: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-94: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-23742 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/zalando/skipper/security/advisories/GHSA-cc8m-98fm-rc9gCVE reference · x_refsource_CONFIRM
- https://github.com/zalando/skipper/commit/0b52894570773b29e2f3c571b94b4211ef8fa714CVE reference · x_refsource_MISC
- https://github.com/zalando/skipper/releases/tag/v0.23.0CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Execution with Unnecessary Privileges
Execution with Unnecessary Privileges represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Insufficiently Protected Credentials
Insufficiently Protected Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Control of Generation of Code ('Code Injection')
Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.