CVE-2026-47205 (GCVE-0-2026-47205)

Vulnerability from cvelistv5 – Published: 2026-06-26 18:01 – Updated: 2026-06-27 02:54
VLAI
Title
Envoy: ext_authz Use-After-Free during Stream Teardown with Per-Route Overrides
Summary
Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.36.0 until 1.36.9, 1.37.5, and 1.38.3, a Use-After-Free (UAF) vulnerability leading to a sudden segmentation fault exists in Envoy's ext_authz HTTP filter when processing per-route authorization overrides concurrently with rapid downstream client disconnects. During standard request lifecycles, Envoy instantiates the ext_authz filter with a foundational authorization client object (client_). If a matched route dictates a dynamic per-route HTTP or gRPC authorization service override, the filter generates a localized client. In the vulnerable implementation, this transient client aggressively overwrote the default client_ unique pointer by executing client_ = std::move(per_route_client). When a client rapidly establishes and subsequently tears down a stream (such as rapidly refreshing a protected WebSocket endpoint), the downstream triggers the ConnectionManagerImpl::doDeferredStreamDestroy() -> ActiveStream::onResetStream() lifecycle. Envoy immediately sequences Filter::onDestroy() in an attempt to securely abort dispatched asynchronous authorization check transactions via client_->cancel(). By destructing the default client abruptly during initiateCall, a memory lifecycle misalignment occurs within the async client manager. The stream teardown fails to reliably track and cancel the dynamically bound asynchronous authorization tasks, orchestrating a sequence where a late asynchronous callback from the network evaluates against a heavily destroyed ActiveStream validation span, generating a UAF process crash. This vulnerability is fixed in 1.36.9, 1.37.5, and 1.38.3.
Severity
5.9 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-27 02:54 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
envoyproxy envoy Affected: >= 1.38.0, < 1.38.3
Affected: >= 1.37.0, < 1.37.5
Affected: >= 1.36.0, < 1.36.9
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-47205",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-27T02:54:07.255044Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-27T02:54:47.509Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "envoy",
          "vendor": "envoyproxy",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.38.0, \u003c 1.38.3"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.37.0, \u003c 1.37.5"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.36.0, \u003c 1.36.9"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.36.0 until 1.36.9, 1.37.5, and 1.38.3, a Use-After-Free (UAF) vulnerability leading to a sudden segmentation fault exists in Envoy\u0027s ext_authz HTTP filter when processing per-route authorization overrides concurrently with rapid downstream client disconnects. During standard request lifecycles, Envoy instantiates the ext_authz filter with a foundational authorization client object (client_). If a matched route dictates a dynamic per-route HTTP or gRPC authorization service override, the filter generates a localized client. In the vulnerable implementation, this transient client aggressively overwrote the default client_ unique pointer by executing client_ = std::move(per_route_client). When a client rapidly establishes and subsequently tears down a stream (such as rapidly refreshing a protected WebSocket endpoint), the downstream triggers the ConnectionManagerImpl::doDeferredStreamDestroy() -\u003e ActiveStream::onResetStream() lifecycle. Envoy immediately sequences Filter::onDestroy() in an attempt to securely abort dispatched asynchronous authorization check transactions via client_-\u003ecancel(). By destructing the default client abruptly during initiateCall, a memory lifecycle misalignment occurs within the async client manager. The stream teardown fails to reliably track and cancel the dynamically bound asynchronous authorization tasks, orchestrating a sequence where a late asynchronous callback from the network evaluates against a heavily destroyed ActiveStream validation span, generating a UAF process crash. This vulnerability is fixed in 1.36.9, 1.37.5, and 1.38.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416: Use After Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-26T18:01:07.766Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j"
        }
      ],
      "source": {
        "advisory": "GHSA-mvh9-767w-x47j",
        "discovery": "UNKNOWN"
      },
      "title": "Envoy: ext_authz Use-After-Free during Stream Teardown with Per-Route Overrides"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-47205",
    "datePublished": "2026-06-26T18:01:07.766Z",
    "dateReserved": "2026-05-18T22:25:21.257Z",
    "dateUpdated": "2026-06-27T02:54:47.509Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-47205",
      "date": "2026-09-27",
      "epss": "0.00387",
      "percentile": "0.30201"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "envoy",
                "vendor": "envoyproxy",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= 1.38.0, \u003c 1.38.3"
                  },
                  {
                    "status": "affected",
                    "version": "\u003e= 1.37.0, \u003c 1.37.5"
                  },
                  {
                    "status": "affected",
                    "version": "\u003e= 1.36.0, \u003c 1.36.9"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "B1146A14-3C49-48C3-BC2A-1BBB202EBD84",
                    "versionEndExcluding": "1.36.9",
                    "versionStartIncluding": "1.36.0",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "2057BF79-00D1-4154-9DC0-3F278C72F4E1",
                    "versionEndExcluding": "1.37.5",
                    "versionStartIncluding": "1.37.0",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "2A218AD4-BF4B-46EA-96D7-3B25B7E71AC8",
                    "versionEndExcluding": "1.38.3",
                    "versionStartIncluding": "1.38.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.36.0 until 1.36.9, 1.37.5, and 1.38.3, a Use-After-Free (UAF) vulnerability leading to a sudden segmentation fault exists in Envoy\u0027s ext_authz HTTP filter when processing per-route authorization overrides concurrently with rapid downstream client disconnects. During standard request lifecycles, Envoy instantiates the ext_authz filter with a foundational authorization client object (client_). If a matched route dictates a dynamic per-route HTTP or gRPC authorization service override, the filter generates a localized client. In the vulnerable implementation, this transient client aggressively overwrote the default client_ unique pointer by executing client_ = std::move(per_route_client). When a client rapidly establishes and subsequently tears down a stream (such as rapidly refreshing a protected WebSocket endpoint), the downstream triggers the ConnectionManagerImpl::doDeferredStreamDestroy() -\u003e ActiveStream::onResetStream() lifecycle. Envoy immediately sequences Filter::onDestroy() in an attempt to securely abort dispatched asynchronous authorization check transactions via client_-\u003ecancel(). By destructing the default client abruptly during initiateCall, a memory lifecycle misalignment occurs within the async client manager. The stream teardown fails to reliably track and cancel the dynamically bound asynchronous authorization tasks, orchestrating a sequence where a late asynchronous callback from the network evaluates against a heavily destroyed ActiveStream validation span, generating a UAF process crash. This vulnerability is fixed in 1.36.9, 1.37.5, and 1.38.3."
          }
        ],
        "id": "CVE-2026-47205",
        "lastModified": "2026-06-29T18:21:30.567",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 5.9,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.2,
              "impactScore": 3.6,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-47205",
                "options": [
                  {
                    "exploitation": "poc"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-27T02:54:07.255044Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-06-26T19:16:40.853",
        "references": [
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Vendor Advisory",
              "Exploit",
              "Mitigation"
            ],
            "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j"
          },
          {
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "tags": [
              "Vendor Advisory",
              "Exploit",
              "Mitigation"
            ],
            "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-416"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-02T19:16:49+00:00",
      "cve": "CVE-2026-47205",
      "id": "CVE-2026-47205",
      "initial_release_date": "2026-06-26T18:01:07.766000+00:00",
      "product_status:known_not_affected": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "envoy: Envoy: ext_authz Use-After-Free during Stream Teardown with Per-Route Overrides",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-47205.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-06-30T01:44:58Z",
      "cve": "CVE-2026-47205",
      "id": "CVE-2026-47205",
      "initial_release_date": "2026-06-30T01:44:58Z",
      "product_status:recommended": "3",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-47205",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-47205.json",
      "version": "2"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-47205",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-06-27T02:54:07.255044Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-06-27T02:54:36.478Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "references": [
              {
                "tags": [
                  "exploit"
                ],
                "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j"
              }
            ],
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "envoy",
              "vendor": "envoyproxy",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003e= 1.38.0, \u003c 1.38.3"
                },
                {
                  "status": "affected",
                  "version": "\u003e= 1.37.0, \u003c 1.37.5"
                },
                {
                  "status": "affected",
                  "version": "\u003e= 1.36.0, \u003c 1.36.9"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.36.0 until 1.36.9, 1.37.5, and 1.38.3, a Use-After-Free (UAF) vulnerability leading to a sudden segmentation fault exists in Envoy\u0027s ext_authz HTTP filter when processing per-route authorization overrides concurrently with rapid downstream client disconnects. During standard request lifecycles, Envoy instantiates the ext_authz filter with a foundational authorization client object (client_). If a matched route dictates a dynamic per-route HTTP or gRPC authorization service override, the filter generates a localized client. In the vulnerable implementation, this transient client aggressively overwrote the default client_ unique pointer by executing client_ = std::move(per_route_client). When a client rapidly establishes and subsequently tears down a stream (such as rapidly refreshing a protected WebSocket endpoint), the downstream triggers the ConnectionManagerImpl::doDeferredStreamDestroy() -\u003e ActiveStream::onResetStream() lifecycle. Envoy immediately sequences Filter::onDestroy() in an attempt to securely abort dispatched asynchronous authorization check transactions via client_-\u003ecancel(). By destructing the default client abruptly during initiateCall, a memory lifecycle misalignment occurs within the async client manager. The stream teardown fails to reliably track and cancel the dynamically bound asynchronous authorization tasks, orchestrating a sequence where a late asynchronous callback from the network evaluates against a heavily destroyed ActiveStream validation span, generating a UAF process crash. This vulnerability is fixed in 1.36.9, 1.37.5, and 1.38.3."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 5.9,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-416",
                  "description": "CWE-416: Use After Free",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-06-26T18:01:07.766Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-mvh9-767w-x47j"
            }
          ],
          "source": {
            "advisory": "GHSA-mvh9-767w-x47j",
            "discovery": "UNKNOWN"
          },
          "title": "Envoy: ext_authz Use-After-Free during Stream Teardown with Per-Route Overrides"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-47205",
        "datePublished": "2026-06-26T18:01:07.766Z",
        "dateReserved": "2026-05-18T22:25:21.257Z",
        "dateUpdated": "2026-06-27T02:54:47.509Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

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.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.