CVE-2026-26308
Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation
描述
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.
如何修補 CVE-2026-26308
要修補 CVE-2026-26308,請將受影響套件升級到下列已修補版本。
- —升級至 1.34.13 或更新版本
- —升級至 1.37.1 或更新版本
CVE-2026-26308 正在被利用嗎?
低 — EPSS 為 0.3%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0, < 1.34.13, >= 1.35.0, < 1.35.9, >= 1.36.0, < 1.36.5, >= 1.37.0, < 1.37.1
- >= 1.37.0, < 1.37.1
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N |