{"id":"BIT-envoy-2026-48706","summary":"Envoy Heap Buffer Overflow in TcpStatsdSink","details":"Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.34.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, a vulnerability exists in Envoy's TCP StatsD sink (TcpStatsdSink), where the thread-local flusher buffer can be overflowed by exceptionally long statistic names (e.g., \u003e16KiB). During formatting, TcpStatsdSink reserves a single contiguous memory slice of 16KiB (FLUSH_SLICE_SIZE_BYTES). If formatting a single metric exceeds the remaining capacity, the flusher initiates a buffer rotation but incorrectly continues to allocate another fixed 16KiB slice. If an attacker can trigger a statistic name longer than 16KiB—for example, by sending an HTTP or gRPC request with an extremely long request path (:path) that is recorded by the grpc_stats filter configured with stats_for_all_methods: true—the flusher will attempt to copy the metric name using memcpy operations beyond the allocated heap buffer boundaries. This leads to a heap write overflow, which can cause immediate denial-of-service (process crash) or potential remote code execution (RCE). This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.","aliases":["CVE-2026-48706","GHSA-7q3f-gwg7-j8g4"],"modified":"2026-09-08T08:47:31.965696660Z","published":"2026-06-30T23:39:38.029Z","database_specific":{"severity":"High","cpes":["cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*"]},"references":[{"type":"ADVISORY","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-7q3f-gwg7-j8g4"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48706"}],"affected":[{"package":{"name":"envoy","ecosystem":"Bitnami","purl":"pkg:bitnami/envoy"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.34.0"},{"fixed":"1.35.13"},{"introduced":"1.36.0"},{"fixed":"1.36.9"},{"introduced":"1.37.0"},{"fixed":"1.37.5"},{"introduced":"1.38.0"},{"fixed":"1.38.3"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/envoy/BIT-envoy-2026-48706.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}],"schema_version":"1.9.0"}