Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.26.10, zalando/skipper's OpenPolicyAgent integration silently bypasses request-body inspection on HTTP/1.1 Transfer-Encoding: chunked and HTTP/2 requests that omit the content-length pseudo-header, because the opaAuthorizeRequestWithBody filter and OpenPolicyAgentInstance.ExtractHttpBodyOptionally in filters/openpolicyagent/openpolicyagent.go produce an empty raw_body and input.parsed_body while the upstream service receives the full attacker-controlled body. This issue is fixed in version 0.26.10.
https://github.com/zalando/skipper/security/advisories/GHSA-659f-rgp5-w4wf
https://github.com/zalando/skipper/releases/tag/v0.26.10
https://github.com/zalando/skipper/pull/4041
https://github.com/zalando/skipper/commit/3152f3b0bb52ca89c3564be42434db0a2a1cea23
Published: 2026-07-17
Updated: 2026-07-23
Base Score: 9.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N
Severity: High
Base Score: 10
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Severity: Critical
Base Score: 7.8
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Severity: High
EPSS: 0.0055