CVE-2019-9512 Some HTTP/2 implementations are vulnerable to ping floods, potentially leading to a denial of service
Attackers can cause denial of service by sending continuous HTTP/2 pings, exhausting CPU and memory resources in vulnerable server implementations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2019-9512?
CVE-2019-9512 is a high-severity denial of service vulnerability in Apache Traffic Server, published on 13 Aug 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Some HTTP/2 implementations are vulnerable to ping floods, potentially leading to a denial of service. The attacker sends continual pings to an HTTP/2 peer, causing the peer to build an internal queue of responses. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.
Weakness: CWE-400
Which versions are affected by CVE-2019-9512?
It affects 4 products.
Products include Apache Traffic Server, Apple Swiftnio, Debian Debian Linux, Nodejs Node.js.
How do I fix CVE-2019-9512?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2019-9512 being exploited?
There is no known exploitation of CVE-2019-9512 in the wild and no public exploit code.
Other vulnerabilities in Apache Traffic Server
Sources
Also known as ALPINE-CVE-2019-9512, AZL-38449, CLEANSTART-2025-JL64950, CLEANSTART-2026-BX90561, CLEANSTART-2026-MG54494, CVE-2019-14988 and 2 more.