CVE-2026-73552 Envoy - Authorization Bypass

Envoy < 1.36.10, 1.37.6, 1.38.4, and 1.39.1 contains an authorization bypass caused by improper handling of opaque header bytes in HTTP RBAC safe_regex evaluation, letting downstream clients bypass RBAC policies, exploit requires crafted opaque header bytes.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
Proof of concept available
Authentication
Not required
EPSS
0.47% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Authorization Bypass
Impact
Broken Access Control
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published
21 September 2026
Updated
15 October 2026
Weakness
CWE-20

Vendor fix

Update to versions 1.36.10, 1.37.6, 1.38.4, or 1.39.1 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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