CVE-2026-65838 Details
Description
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.
A vulnerability exists in Zalando Skipper versions prior to 0.27.35, specifically within the 'opaAuthorizeRequestWithBody' filter. This issue allows an oversized declared 'Content-Length' in requests to bypass Rego policies that deny on presence. The problem arises because the 'ExtractHttpBodyOptionally' function leaves the Open Policy Agent (OPA) with an empty parsed body while forwarding the complete request body to the upstream service. As a result, policies that rely on inspecting the request body can fail open, allowing forbidden content to reach the protected service. The vulnerability affects deployments that use body-based authorization with OPA and exceed the default maximum request body size of 1 MB.
Users are advised to update to Skipper version 0.27.35 or later. Additionally, OPA policy authors should ensure that their policies check the 'input.attributes.request.http.truncated_body' attribute to properly handle request bodies that may be oversized or chunked.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 14, 2026CISA-ADP
Assessed Sep 15, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/zalando/skipper/commit/2cfceabaa6ff0af65b312dcb9bcbe84691b9d507 | [email protected] | Source CodeVendor |
| https://github.com/zalando/skipper/releases/tag/v0.27.35 | [email protected] | Release NotesVendor |
| https://github.com/zalando/skipper/security/advisories/GHSA-8qqm-fp2q-v734 | [email protected] | AdvisoryBundleRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-754 | Improper Check for Unusual or Exceptional Conditions | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Zalando Skipper | < 0.27.35 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 15, 2026 | CVE Modified | CISA-ADP |
| Sep 14, 2026 | New CVE Received | [email protected] |