Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-23742 is a high-severity Code Injection (CWE-94) vulnerability in Zalando Skipper. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked at the 39th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-6 (Least Privilege) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-23742 affects Skipper, an HTTP router and reverse proxy for service composition, in versions before 0.23.0. The vulnerability stems from the default configuration flag -lua-sources=inline,file, which permits the execution of inline Lua scripts. If untrusted users can create Lua filters—such as through a Kubernetes Ingress resource—they can inject scripts that access the filesystem available to the Skipper process. Additionally, if attackers can read Skipper logs, they can extract skipper secrets. The issue is associated with CWEs-94 (code injection), CWE-250 (execution with unnecessary privileges), and CWE-522 (insufficiently protected credentials), with a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
Attackers require low privileges (PR:L) and can exploit this remotely over the network (AV:N) with low complexity and no user interaction. A malicious user with the ability to create Lua filters can execute arbitrary code to read sensitive filesystem contents accessible to the Skipper process. If they also have log access, they can retrieve skipper secrets, potentially leading to high confidentiality, integrity, and availability impacts.
The vulnerability is fixed in Skipper version 0.23.0. Official mitigation guidance is available in the GitHub security advisory (GHSA-cc8m-98fm-rc9g), the release notes for v0.23.0, and the fixing commit (0b52894570773b29e2f3c571b94b4211ef8fa714), which recommend updating to the patched version and avoiding the vulnerable default Lua source configuration.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2860
Vulnerability Data
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.…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 7 hardening rules · 6 OS baselines
V10.2.3V13.2.2V11.3.3V1.3.1
Mitigating Controls (NIST 800-53 r5) AI
Protection of information at rest requires encryption or equivalent safeguards for stored credentials.
Transmission confidentiality and integrity enforcement stops credentials from being sent in plaintext or without protection.
Least privilege directly requires that only the minimum necessary authorizations are granted, structurally eliminating execution with unnecessary privileges.
Developer testing and evaluation finds code paths that accept and execute externally influenced strings.
Input validation directly stops untrusted data from being used to construct executable code without neutralization.
Authenticator management requires secure generation, storage, and distribution of credentials, directly stopping insecure methods.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Encrypting data-at-rest fully prevents insecure credential storage while only partially satisfying the broader data-protection outcome.
Encrypting data-in-transit fully prevents interception of credentials in motion while only partially satisfying the broader data-protection outcome.
Credential management practices directly reduce insecure storage/transmission but do not guarantee encryption or transport protection.
Protecting identity assertions covers conveyance of credentials but is narrower than full credential lifecycle protection.
PR.AA-05 directly enforces least privilege so largely eliminates CWE-250 at design time, yet the weakness can still arise from runtime escalation paths, third-party code, or misapplied role definitions outside this single control.
PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Requiring protected storage, transmission, and non-display of passwords prevents credentials from being stored or sent in clear text where they can be harvested by unauthorized actors.
Requiring explicit justification and time-limited grants discourages the routine allocation of unnecessary privileges that would otherwise allow execution with more rights than required.
Restricting privileged utilities to the fewest trusted users and requiring explicit authorization directly stops developers or operators from embedding or invoking code that runs with unnecessary elevated rights.
Mandating separate non-privileged identities for routine work and restricting privileged accounts to administrative tasks reduces the chance that everyday operations run with unnecessary elevated rights.
Protecting secret and private keys against disclosure and unauthorized use decreases the exposure of credentials that are stored or transmitted in recoverable form.
Forbidding clear-text transmission and display of passwords, plus the use of stronger alternatives to passwords, prevents credentials from being obtained or reused by attackers.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Windows 10 (1 rule)
- V-220712 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-250
Windows 11 (1 rule)
- V-253269 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-250
Windows Server 2016 (1 rule)
- V-225007 Only administrators responsible for the member server or standalone or nondomain-joined system must have Administrator rights on the system. prevents CWE-250
Windows Server 2019 (1 rule)
- V-205746 Windows Server 2019 must only allow Administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-250
Windows Server 2022 (1 rule)
- V-254428 Windows Server 2022 must only allow administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-250