CVE-2026-48044
Envoy Zstd Decompressor: Ratio Check at Wrong Loop Depth lead to memory explosion
HIGH 7.5
At a glance
- Source
- NVD
- EPSS
- EPSS 0.49 % · percentile 42 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.23.0 until 1.35.11, 1.36.7, 1.37.3, and 1.38.1, a vulnerability has been identified in Envoy's zstd decompressor implementation (ZstdDecompressorImpl). When zstd decompression is enabled, processing a specially crafted, highly compressed zstd payload can lead to massive memory allocation. An attacker can exploit this to cause severe memory exhaustion, potentially resulting in an Out-Of-Memory (OOM) kill and Denial of Service (DoS) for the Envoy proxy. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.
Weaknesses (CWE)
- CWE-409 — Improper Handling of Highly Compressed Data (Data Amplification)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-39820
- GCVE · GCVE-0-2026-48044
Affected configurations (NVD CPE)
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*≥ 1.23.0 < 1.35.13cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*≥ 1.36.0 < 1.36.9cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*≥ 1.37.0 < 1.37.5cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*≥ 1.38.0 < 1.38.3
Affected products
| Product | Versions |
|---|---|
| envoyproxy · envoy | affected >= 1.38.0, < 1.38.1 ; affected >= 1.37.0, < 1.37.3 ; affected >= 1.36.0, < 1.36.7 ; affected >= 1.23.0, < 1.35.11 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |