CVE-2019-18801 - CVE House
Back to Database
Status published Critical CVE-2019-18801

An issue was discovered in Envoy 1.12.0. An untrusted remote...

Vulnerability Description

An issue was discovered in Envoy 1.12.0. 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. This may be used to corrupt nearby heap contents (leading to a query-of-death scenario) or may be used to bypass Envoy's access control mechanisms such as path based routing. An attacker can also modify requests from other users that happen to be proximal temporally and spatially.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2019-18801

Credits & Attribution

No credits recorded in the NVD database.

References

More from envoyproxy

View All →
CVE-2025-66220
Envoy’s TLS certificate matcher for `match_typed_subject_alt_names` may incorrectly treat certificates containing an embedded null byte
Medium 5
CVE-2025-64763
Envoy forwards early CONNECT data in TCP proxy mode
Low 3.7
CVE-2025-64527
Envoy crashes when JWT authentication is configured with the remote JWKS fetching
Medium 6.5
CVE-2025-62504
Envoy Lua filter use-after-free when oversized rewritten response body causes crash
Medium 6.5
CVE-2025-62409
Envoy allows large requests and responses to cause TCP connection pool crash
Medium 6.6

Affected Vendor

Affected Software

envoy
Vulnerable Versions:
0

Timeline

Official Publish: December 13th, 2019
Last Modified: August 5th, 2024
Added to House: July 20th, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.