What’s Vulnerable › Vulnerabilities

CVE-2019-18838

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2019-12-13 · updated 2026-06-17
• Weakness: CWE-476

Description

An issue was discovered in Envoy 1.12.0. Upon receipt of a malformed HTTP request without a Host header, it sends an internally generated "Invalid request" response. This internally generated response is dispatched through the configured encoder filter chain before being sent to the client. An encoder filter that invokes route manager APIs that access a request's Host header causes a NULL pointer dereference, resulting in abnormal termination of the Envoy process.

Affected products

• envoyproxy envoy: through 1.12.1

References

• https://blog.envoyproxy.io
• https://github.com/envoyproxy/envoy/commits/master
• https://github.com/envoyproxy/envoy/security/advisories/GHSA-f2rv-4w6x-rwhc
• https://groups.google.com/forum/#%21forum/envoy-users
• https://blog.envoyproxy.io
• https://github.com/envoyproxy/envoy/commits/master
• https://github.com/envoyproxy/envoy/security/advisories/GHSA-f2rv-4w6x-rwhc
• https://groups.google.com/forum/#%21forum/envoy-users

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