Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2019-18801

29
FAUCET Score

CVE-2019-18801 is a critical heap overflow vulnerability in Envoy 1.12.0, where untrusted remote clients can send crafted HTTP/2 requests to an HTTP/1 upstream, causing writes outside of request buffers. This allows for potential heap corruption, leading to denial-of-service, bypass of access control, or modification of other users' requests. With a CVSS score of 9.8 (CRITICAL), it presents a severe risk due to its network-based attack vector, low attack complexity, and high impact on confidentiality, integrity, and availability. Currently, there is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
<= 1.12.1CPE matchmatch criteria
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

9.8CRITICAL

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
2.50%
Probability of exploitation in next 30 days
EPSS Percentile
83.0%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0250 is in the 73rd percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (8)

github_advisorypatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Openshift Service Mesh 1.0Fixed in: kiali-0:v1.0.8.redhat1-1.el7
View patch
redhatpatch availablevia redhat_api
Product: OpenShift Service Mesh 1.0Fixed in: servicemesh-0:1.0.3-1.el8
View patch
redhatpatch availablevia redhat_api
Product: OpenShift Service Mesh 1.0Fixed in: servicemesh-cni-0:1.0.3-1.el8
View patch
redhatpatch availablevia redhat_api
Product: OpenShift Service Mesh 1.0Fixed in: servicemesh-grafana-0:6.2.2-25.el8
View patch
redhatpatch availablevia redhat_api
Product: OpenShift Service Mesh 1.0Fixed in: servicemesh-operator-0:1.0.3-1.el8
View patch
redhatpatch availablevia redhat_api
Product: OpenShift Service Mesh 1.0Fixed in: servicemesh-prometheus-0:2.7.2-26.el8
View patch
redhatpatch availablevia redhat_api
Product: OpenShift Service Mesh 1.0Fixed in: servicemesh-proxy-0:1.0.3-1.el8
View patch

Vendor Advisories (1)

redhatCVE-2019-18801Critical

envoy: an untrusted remote client may send HTTP/2 requests that write to the heap outside of the request buffers when the upstream is HTTP/1

Dec 10, 2019

References

access.redhat.com / errata/RHSA-2019:4222
Third Party Advisory
blog.envoyproxy.io
Product
github.com / envoyproxy/envoy/commits/master
Patch
github.com / envoyproxy/envoy/security/advisories/GHSA-gxvv-x4p2-rppp
ExploitThird Party Advisory
groups.google.com / forum