Incorrect Authorization Affecting ecs-service-connect-agent package, versions <0:v1.34.13.0-1.amzn2023


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.29% (21st percentile)

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  • Snyk IDSNYK-AMZN2023-ECSSERVICECONNECTAGENT-15922156
  • published7 Apr 2026
  • disclosed10 Mar 2026

Introduced: 10 Mar 2026

CVE-2026-26308  (opens in a new tab)
CWE-863  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 ecs-service-connect-agent to version 0:v1.34.13.0-1.amzn2023 or higher.
This issue was patched in ALAS2023-2026-1532.

NVD Description

Note: Versions mentioned in the description apply only to the upstream ecs-service-connect-agent package and not the ecs-service-connect-agent package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

Envoy is a high-performance edge/middle/service proxy. Prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13, the Envoy RBAC (Role-Based Access Control) filter contains a logic vulnerability in how it validates HTTP headers when multiple values are present for the same header name. Instead of validating each header value individually, Envoy concatenates all values into a single comma-separated string. This behavior allows attackers to bypass RBAC policies—specifically "Deny" rules—by sending duplicate headers, effectively obscuring the malicious value from exact-match mechanisms. This vulnerability is fixed in 1.37.1, 1.36.5, 1.35.8, and 1.34.13.

CVSS Base Scores

version 3.1