CVE-2026-61674
fluent-bit: Fluent Bit: Remote stack buffer overflow in Fluent Bit `out_forward` Secure-Forward `PONG` handler
Sévérité par source
Le label propre à Trivy est CRITICAL. Critique selon Red Hat, Azure Linux, Bitnami.
Description
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.
Paquets affectés et versions corrigées
| Source | Paquet | Corrigé en |
|---|---|---|
| Azure Linux 3.0 | fluent-bit | 0:3.1.10-8.azl3 |
| bitnami::Bitnami Vulnerability Database | fluent-bit | 5.0.8 |
Références
- https://access.redhat.com/security/cve/CVE-2026-61674
- https://github.com/fluent/fluent-bit/commit/45486556be9d023e194665e243f156b228e195e0
- https://github.com/fluent/fluent-bit/pull/11945
- https://github.com/fluent/fluent-bit/releases/tag/v5.0.8
- https://github.com/fluent/fluent-bit/security/advisories/GHSA-jrp8-r9hx-gf73
- https://nvd.nist.gov/vuln/detail/CVE-2026-61674
- https://www.cve.org/CVERecord?id=CVE-2026-61674