What’s Vulnerable › Vulnerabilities

CVE-2026-65838: 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

• Severity: high (CVSS 8.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-14 · updated 2026-09-16
• Weakness: CWE-754

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.

Affected products

• zalando skipper: before 0.27.35

References

• https://github.com/zalando/skipper/commit/2cfceabaa6ff0af65b312dcb9bcbe84691b9d507
• https://github.com/zalando/skipper/releases/tag/v0.27.35
• https://github.com/zalando/skipper/security/advisories/GHSA-8qqm-fp2q-v734

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