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No exploitation reportedFix available

CVE-2019-18802

No exploitation reported by the sources we read.

  • Published2019-12-13

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2019-12-1313:15CVE publishedNVD

Versions per branch

NVD
Envoy
BranchAffectedFixed in
1.12≤ 1.12.1no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • kialiRed Hat:service_mesh:1.0::el7all versions · fixed in 0:v1.0.8.redhat1-1.el7
  • nghttp2SUSE:Linux Enterprise Module for Basesystem 15 SP1all versions · fixed in 1.40.0-3.6.3
  • nghttp2openSUSE:Tumbleweedall versions · fixed in 1.64.0-1.1
  • nghttp2openSUSE:Leap 15.2all versions · fixed in 1.40.0-lp152.2.3.1and 1 other package
  • nghttp2openSUSE:Leap 15.1all versions · fixed in 1.40.0-lp151.3.6.1and 1 other package
  • nghttp2Mageia:7all versions · fixed in 1.38.0-1.2.mga7
  • servicemeshRed Hat:service_mesh:1.0::el8all versions · fixed in 0:1.0.3-1.el8and 11 other packages
  • servicemesh-grafanaRed Hat:service_mesh:1.0::el8all versions · fixed in 0:6.2.2-25.el8and 1 other package

1 more package range on OSV.dev

Vendor advisories

  • CVE-2019-18802 Red Hat Product Security23 products fixed

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

  • RHSA-2019:4222 Red Hat Product Security23 products fixed

    Red Hat Security Advisory: Red Hat OpenShift Service Mesh 1.0.3 RPMs security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2019:4222 · 23 productsThe OpenShift Service Mesh release notes provide information on the features and known issues: https://docs.openshift.com/container-platform/4.2/service_mesh/servicemesh-release-notes.html

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2019-12-13
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-fx83-72pw-c56f

Frequently asked questions

What is CVE-2019-18802?

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.

Is CVE-2019-18802 actively exploited?

Active exploitation of CVE-2019-18802 has not been confirmed. Its EPSS score was 2.5% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2019-18802?

CVE-2019-18802 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record