CVE-2026-83603 Netdata: Local Root via ndsudo Arbitrary socket_path → fail2ban-client Pickle RCE
A local attacker can escalate privileges to root by manipulating a socket path to trigger unsafe deserialization in fail2ban-client via Netdata's ndsudo helper.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-83603?
CVE-2026-83603 is a high-severity unsafe deserialization vulnerability in netdata, published on 22 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Netdata is an open source observability tool. Prior to 2.10.4, the setuid-root ndsudo helper command fail2ban-client-status-socket in src/collectors/utils/ndsudo.c accepts a caller-controlled --socket_path from the low-privileged netdata service account. The account can direct root fail2ban-client to a malicious UNIX socket, and fail2ban/client/csocket.py CSocket.receive() passes the returned data to pickle.loads(), allowing attacker-controlled code to execute as root on systems with fail2ban-client installed. This issue is fixed in version 2.10.4 and nightly build 2.10.0-782-nightly.
Which versions are affected by CVE-2026-83603?
How do I fix CVE-2026-83603?
Upgrade to a fixed version.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-83603 being exploited?
There is no known exploitation of CVE-2026-83603 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as DEBIAN-CVE-2026-83603, GHSA-qwh9-pq27-993w, MINI-9355-ffhc-6gmq, MINI-p8jc-2842-wpwr, UBUNTU-CVE-2026-83603.