Use-after-free in envoy - CVE-2026-73513
Published: August 26, 2026
Vulnerability identifier: #VU145868
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-2026-73513
CWE-ID: CWE-416
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 use-after-free in common/http/http2 when processing upstream HTTP/2 response trailers without the END_STREAM flag while using oghttp2. A remote attacker can send specially crafted upstream HTTP/2 response headers and trailers to cause a denial of service.
Only the upstream HTTP/2 client path is reachable, and exploitation requires the oghttp2 codec to be enabled.
Affected software
envoy
Istio
Istio
How to mitigate CVE-2026-73513
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