Improper check for unusual conditions in zalando skipper
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.27.35, the opaAuthorizeRequestWithBody filter in filters/openpolicyagent/openpolicyagent.go can allow an oversized declared Content-Length request to bypass a deny-on-presence Rego policy because ExtractHttpBodyOptionally leaves OPA with an empty parsed_body while forwarding the complete request body upstream. This incomplete remediation of CVE-2026-50197 affects deployments that authorize request-body content and exceed -open-policy-agent-max-request-body-size, which defaults to 1 MB. Policy logic that does not reject input.attributes.request.http.truncated_body can therefore fail open and permit a forbidden payload to reach the protected service, while small bodies and the previously fixed chunked-body case are evaluated normally. This issue is fixed in version 0.27.35.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| zalando | skipper | before 0.27.35 | 0.27.35 | Patch available | CNA |
| — | github.com/zalando/skipper (Go) | before 0.27.26 | 0.27.26 | Patch available | GHSA-8qqm-fp2q-v734 |
- skipper Vendorzalando Affected before 0.27.35 Fixed in 0.27.35 Patch available CNA
- github.com/zalando/skipper (Go) Vendor— Affected before 0.27.26 Fixed in 0.27.26 Patch available GHSA-8qqm-fp2q-v734
Remediation
- Fix · CNA skipper (zalando) Fixed in 0.27.35
- Fix · GHSA-8qqm-fp2q-v734 github.com/zalando/skipper (Go) Fixed in 0.27.26 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-65838
- 2026-10-03 Alias added: GHSA-8qqm-fp2q-v734
References
Other 5
- https://github.com/zalando/skipper/security/advisories/GHSA-8qqm-fp2q-v734
- https://github.com/zalando/skipper/commit/2cfceabaa6ff0af65b312dcb9bcbe84691b9d507
- https://github.com/zalando/skipper/releases/tag/v0.27.35
- https://github.com/zalando/skipper
- https://github.com/zalando/skipper/releases/tag/v0.27.26
More zalando vulnerabilities
- TI-2026-46767 Skipper Incomplete Fix for CVE-2026-50197 Policy Bypass CVSS 4.0HIGH 8.8
- TI-2026-36956 Skipper: opaAuthorizeRequestWithBody filter bypasses OPA policy on Transfer-Encoding: chunked / HTTP/2 requests CVSS 4.0HIGH 7.8
- TI-2026-58867 Skipper: OPA body-authz bypass: truncated_body mitigation fails open on chunked/HTTP-2 (incomplete fix CVE-2026-50197) CVSS 3.1HIGH 7.5
- TI-2022-18154 Zalando Skipper v0.13.236 is vulnerable to Server-Side Request Forgery (SSRF). CVSS 3.1CRITICAL 9.8
- TI-2026-19115 Skipper arbitrary code execution through lua filters CVSS 3.1HIGH 8.8
- TI-2026-19725 Skipper Ingress Controller Allows Unauthorized Access to Internal Services via ExternalName CVSS 3.1HIGH 8.1
Sources
- CVE-2026-65838 · CVE Program
- CVE-2026-65838 · NVD
- FIRST EPSS
- GHSA-8qqm-fp2q-v734 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences