{"id":"CVE-2026-65838","aliases":["GHSA-8qqm-fp2q-v734","GO-2026-6019"],"url":"https://o3.security/vulnerability/CVE-2026-65838","summary":"Skipper: an oversized declared-`Content-Length` body still hands OPA an empty `parsed_body`, so deny-on-presence Rego policies fail OPEN while the full payload reaches upstream","details":"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.","published":"2026-09-14T20:01:27.862Z","modified":"2026-09-18T03:30:58.322450938Z","cvss":{"score":8.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N"},"epss":{"score":0.00266,"percentile":0.18935,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/zalando/skipper","fixedVersion":"0.27.26"}],"fix":{"url":"https://github.com/zalando/skipper/commit/2cfceabaa6ff0af65b312dcb9bcbe84691b9d507","label":"zalando/skipper@2cfceab"},"references":[{"type":"WEB","url":"https://github.com/zalando/skipper/releases/tag/v0.27.35"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/65xxx/CVE-2026-65838.json"},{"type":"ADVISORY","url":"https://github.com/zalando/skipper/security/advisories/GHSA-8qqm-fp2q-v734"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-65838"},{"type":"FIX","url":"https://github.com/zalando/skipper/commit/2cfceabaa6ff0af65b312dcb9bcbe84691b9d507"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-18T03:30:58.322450938Z"}}