Incorrect Authorization Affecting github.com/zalando/skipper/filters/openpolicyagent/opaauthorizerequest package, versions <0.27.35


Severity

Recommended
0.0
high
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.5% (42nd percentile)

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  • Snyk IDSNYK-GOLANG-GITHUBCOMZALANDOSKIPPERFILTERSOPENPOLICYAGENTOPAAUTHORIZEREQUEST-19883925
  • published17 Sept 2026
  • disclosed16 Sept 2026
  • creditPig-Tail

Introduced: 16 Sep 2026

NewCVE-2026-86043  (opens in a new tab)
CWE-863  (opens in a new tab)

How to fix?

Upgrade github.com/zalando/skipper/filters/openpolicyagent/opaauthorizerequest to version 0.27.35 or higher.

Overview

Affected versions of this package are vulnerable to Incorrect Authorization through ExtractHttpBodyOptionally in filters/openpolicyagent/openpolicyagent.go and AdaptToExtAuthRequest in filters/openpolicyagent/internal/envoy/skipperadapter.go. An attacker can get an oversized request body authorized and forwarded to the upstream service by sending the request with chunked framing or over HTTP/2 so no Content-Length is present. In that path, Skipper truncates the body for OPA inspection, but the body-truncation signal is not carried into the ext-authz request, so policies that gate on input.truncated_body evaluate as if the body were complete. This lets a remote client bypass body-based access control and send content that the policy was meant to reject, exposing protected actions or data to the upstream application.

CVSS Base Scores

version 4.0
version 3.1