{"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"}}]}}