{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-61674",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-07-10T18:25:21.468Z",
        "datePublished": "2026-09-21T16:10:15.276Z",
        "dateUpdated": "2026-09-21T18:52:25.840Z"
    },
    "containers": {
        "cna": {
            "title": "Fluent Bit: Remote stack buffer overflow in Fluent Bit `out_forward` Secure-Forward `PONG` handler",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-121",
                            "lang": "en",
                            "description": "CWE-121: Stack-based Buffer Overflow",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-787",
                            "lang": "en",
                            "description": "CWE-787: Out-of-bounds Write",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-843",
                            "lang": "en",
                            "description": "CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "HIGH",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 9.2,
                        "baseSeverity": "CRITICAL",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/fluent/fluent-bit/security/advisories/GHSA-jrp8-r9hx-gf73",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/fluent/fluent-bit/security/advisories/GHSA-jrp8-r9hx-gf73"
                },
                {
                    "name": "https://github.com/fluent/fluent-bit/pull/11945",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/fluent/fluent-bit/pull/11945"
                },
                {
                    "name": "https://github.com/fluent/fluent-bit/commit/45486556be9d023e194665e243f156b228e195e0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/fluent/fluent-bit/commit/45486556be9d023e194665e243f156b228e195e0"
                },
                {
                    "name": "https://github.com/fluent/fluent-bit/releases/tag/v5.0.8",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/fluent/fluent-bit/releases/tag/v5.0.8"
                }
            ],
            "affected": [
                {
                    "vendor": "fluent",
                    "product": "fluent-bit",
                    "versions": [
                        {
                            "version": ">= 0.11.0, < 5.0.8",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-09-21T16:10:15.276Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Fluent Bit is a fast and lightweight logs, metrics, and traces processor for Linux, BSD, macOS, and Windows. From 0.11.0 until 5.0.8, plugins/out_forward/forward.c secure_forward_pong copies the server-controlled PONG[2] reason into the 32-byte stack buffer msg with memcpy without checking its MessagePack type or length. An attacker who controls or can impersonate an out_forward Secure Forward destination configured with Shared_Key or Empty_Shared_Key can send an oversized reason during the first handshake and overwrite stack control data. Protected builds reliably terminate, while builds without a stack canary or with a disclosure can allow remote code execution as the Fluent Bit process user. When the opt-in --supervisor mode is used, fork-only respawns preserve the canary and address layout, allowing repeated crash-or-survive probes to support code execution on a hardened build; ordinary exec-based or service-manager restarts do not preserve that state. This issue is fixed in version 5.0.8."
                }
            ],
            "source": {
                "advisory": "GHSA-jrp8-r9hx-gf73",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/fluent/fluent-bit/security/advisories/GHSA-jrp8-r9hx-gf73",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-21T18:51:32.206511Z",
                                "id": "CVE-2026-61674",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-09-21T18:52:25.840Z"
                }
            }
        ]
    }
}