CVE-2019-9900

HIGH 8.3CVE-2019-9900 · Published 25/04/2019 · updated 17/06/2026

In short

CVE-2019-9900 is a HIGH (CVSS 8.3) vulnerability affecting envoy (envoyproxy).
Chance of exploitation in the next 30 days (EPSS): 3.7%, higher than 89.8% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
envoy envoyproxy	`≤ 1.9.0`	No fix yet

Description

When parsing HTTP/1.x header values, Envoy 1.9.0 and before does not reject embedded zero characters (NUL, ASCII 0x0). This allows remote attackers crafting header values containing embedded NUL characters to potentially bypass header matching rules, gaining access to unauthorized resources.

References

access.redhat.com/errata/RHSA-2019:0741 · Third Party Advisory
envoyproxy/envoy · Exploit
envoyproxy/envoy security advisory · Exploit
groups.google.com/forum
envoyproxy.io/docs/envoy/v1.9.1/intro/version_history · Release Notes

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Package

Affected versions

Patched versions

envoy

envoyproxy

≤ 1.9.0

No fix yet

More vulnerabilities in envoy

See all →