envoyproxy envoy up to 1.35.12/1.36.8/1.37.4/1.38.2 buffer overflow

Summaryinfo

A vulnerability classified as critical was found in envoyproxy envoy up to 1.35.12/1.36.8/1.37.4/1.38.2. This affects an unknown part. Executing a manipulation can lead to buffer overflow. This vulnerability is tracked as CVE-2026-48706. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in envoyproxy envoy up to 1.35.12/1.36.8/1.37.4/1.38.2 and classified as problematic. This vulnerability affects an unknown function. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect availability. CVE summarizes:

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., >16KiB). 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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-48706 since 05/22/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

Upgrading to version 1.35.13, 1.36.9, 1.37.5 or 1.38.3 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Firewall Software

Vendor

• envoyproxy

Name

• envoy

Version

• 1.35.0
• 1.35.1
• 1.35.2
• 1.35.3
• 1.35.4
• 1.35.5
• 1.35.6
• 1.35.7
• 1.35.8
• 1.35.9
• 1.35.10
• 1.35.11
• 1.35.12
• 1.36.0
• 1.36.1
• 1.36.2
• 1.36.3
• 1.36.4
• 1.36.5
• 1.36.6
• 1.36.7
• 1.36.8
• 1.37.0
• 1.37.1
• 1.37.2
• 1.37.3
• 1.37.4
• 1.38.0
• 1.38.1
• 1.38.2

License

• free

Website

• Product: https://github.com/envoyproxy/envoy/

CPE 2.3info

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CPE 2.2info

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