Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-03-12 08:39

Modified

2026-03-12 09:10

Summary

Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation

Details

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.

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "envoy",
        "purl": "pkg:bitnami/envoy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.34.13"
            },
            {
              "introduced": "1.35.0"
            },
            {
              "fixed": "1.35.9"
            },
            {
              "introduced": "1.36.0"
            },
            {
              "fixed": "1.36.5"
            },
            {
              "introduced": "1.37.0"
            },
            {
              "fixed": "1.37.1"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-26308"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:go:*:*"
    ],
    "severity": "High"
  },
  "details": "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\u2014specifically \"Deny\" rules\u2014by 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.",
  "id": "BIT-envoy-2026-26308",
  "modified": "2026-03-12T09:10:07.191Z",
  "published": "2026-03-12T08:39:41.078Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/envoyproxy/envoy/commit/b6ba0b2294b98484fb0ed8556897d1073cc27867"
    },
    {
      "type": "WEB",
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-ghc4-35x6-crw5"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-26308"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation"
}

CVE-2026-26308 (GCVE-0-2026-26308)

Vulnerability from cvelistv5 – Published: 2026-03-10 19:01 – Updated: 2026-03-10 20:12

Title

Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation

Summary

Severity ?

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N

CWE

CWE-863 - Incorrect Authorization

Assigner

GitHub_M

References

URL

Tags

	https://github.com/envoyproxy/envoy/security/advi…	x_refsource_CONFIRM
	https://github.com/envoyproxy/envoy/commit/b6ba0b…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	envoyproxy	envoy	Affected: >= 1.37.0, < 1.37.1 Affected: >= 1.36.0, < 1.36.5 Affected: >= 1.35.0, < 1.35.9 Affected: < 1.34.13

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-26308",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-10T20:10:29.907912Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-10T20:12:40.604Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "envoy",
          "vendor": "envoyproxy",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.37.0, \u003c 1.37.1"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.36.0, \u003c 1.36.5"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.35.0, \u003c 1.35.9"
            },
            {
              "status": "affected",
              "version": "\u003c 1.34.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u2014specifically \"Deny\" rules\u2014by 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-10T19:01:28.062Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-ghc4-35x6-crw5",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-ghc4-35x6-crw5"
        },
        {
          "name": "https://github.com/envoyproxy/envoy/commit/b6ba0b2294b98484fb0ed8556897d1073cc27867",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/envoyproxy/envoy/commit/b6ba0b2294b98484fb0ed8556897d1073cc27867"
        }
      ],
      "source": {
        "advisory": "GHSA-ghc4-35x6-crw5",
        "discovery": "UNKNOWN"
      },
      "title": "Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-26308",
    "datePublished": "2026-03-10T19:01:28.062Z",
    "dateReserved": "2026-02-13T16:27:51.804Z",
    "dateUpdated": "2026-03-10T20:12:40.604Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

Vulnerability from bitnami_vulndb

CVE-2026-26308 (GCVE-0-2026-26308)

Tags

Sightings

Nomenclature