NULL pointer dereference in envoy - CVE-2026-73547
Published: August 26, 2026
Vulnerability identifier: #VU145866
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-73547
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to null pointer dereference in the ext_authz filter when processing a path-less CONNECT request after applying query parameter mutations from a successful authorization response. A remote attacker can send a specially crafted path-less CONNECT request to cause a denial of service.
Exploitation requires the ext_authz filter to be enabled, the authorization server to return an OK response containing query parameter mutations, and the deployment to accept path-less CONNECT requests.
Affected software
envoy
Istio
Istio
How to mitigate CVE-2026-73547
Install security update from vendor's website.
envoy - addressed in versions 1.36.10, 1.37.6, 1.38.4, 1.39.1
Istio - addressed in versions 1.29.7, 1.30.4
Istio - addressed in versions 1.29.7, 1.30.4