---
title: "CVE-2019-15226: Upon receiving each incoming request… | CubePath"
description: "Upon receiving each incoming request header data, Envoy will iterate over existing request headers to verify that the total size of the headers stays…"
language: en
source: https://cubepath.com/security/cve/CVE-2019-15226
---

# CVE-2019-15226: Upon receiving each incoming request… | CubePath

## Description

Upon receiving each incoming request header data, Envoy will iterate over existing request headers to verify that the total size of the headers stays below a maximum limit. The implementation in versions 1.10.0 through 1.11.1 for HTTP/1.x traffic and all versions of Envoy for HTTP/2 traffic had O(n^2) performance characteristics. A remote attacker may craft a request that stays below the maximum request header size but consists of many thousands of small headers to consume CPU and result in a denial-of-service attack.

Official description from the CVE record, published by mitre. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2019-15226)

## Key data

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.64517 (64.5% probability)

Percentile

99.2%

Scores of

Nov 10, 2026

Model

v2026.06.15

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [github.com/envoyproxy/envoy/commits/master](https://github.com/envoyproxy/envoy/commits/master)
- [github.com/envoyproxy/envoy/commit/afc39bea36fd436e54262f15…](https://github.com/envoyproxy/envoy/commit/afc39bea36fd436e54262f150c009e8d72db5014)
- [github.com/envoyproxy/envoy/issues/8520](https://github.com/envoyproxy/envoy/issues/8520)

## Timeline

1. ID reserved Aug 19, 2019
2. Record published Oct 9, 2019
3. Record last updated Aug 5, 2024

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:03 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)