CVE-2019-18802

envoy: malformed request header may cause bypass of route matchers resulting in escalation of privileges or information disclosure

Published 13 Dec 2019Modified 17 Jun 2026

In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.

Severity by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Red Hat7.5CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Trivy's own label is CRITICAL. Rated critical by NVD, Photon OS. Rated lower by Red Hat (high).

Description

An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with whitespace after the header content. Envoy will treat "header-value " as a different string from "header-value" so for example with the Host header "example.com " one could bypass "example.com" matchers.

Affected packages and fixed versions

Source	Package	Fixed in
Photon OS 1.0	envoy	1.10.0-6.ph1
Photon OS 2.0	envoy	1.10.0-6.ph2

References

All 9 references

https://www.cve.org/CVERecord?id=CVE-2019-18802

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Vulnerability data compiled from the Trivy vulnerability database (trivy-db, Aqua Security, Apache License 2.0), which aggregates third-party advisories. CVE records are published by The MITRE Corporation under the CVE Terms of Use; CVE is a trademark of MITRE. This product uses data from the NVD API but is not endorsed or certified by the NVD. Severity, titles and advisory data from the GitHub Advisory Database (CC BY 4.0), Red Hat security data (CC BY 4.0) and the other sources linked on each entry. Entries may be summarised or re-formatted; the linked original is the authoritative record.