CVE-2026-82435 Apache Storm Worker: Unauthenticated Remote Memory Exhaustion in the Worker Messaging Decoder
Unauthenticated remote attackers can cause denial of service in Apache Storm Workers by sending crafted frames that trigger excessive memory allocation before authentication.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-82435?
CVE-2026-82435 is a critical denial of service vulnerability in Apache Storm Worker, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Description
The worker's Netty message decoder is installed ahead of the SASL authentication handlers in the pipeline and acts on frames before any authentication has taken place. It allocated buffers sized from a length field carried in the frame, so a single frame from an unauthenticated peer able to reach a worker slot port could drive a large allocation.
`storm.messaging.netty.authentication` defaults to false, and the decoder runs before the handler that enforces it in any case, so no credentials are required. The attacker needs only TCP reachability to a worker port.
The effect of a single frame at the default 768 MB worker heap has not been measured to distinguish sustained worker loss from transient garbage-collection pressure. The severity assigned to this advisory reflects the more conservative reading; consumers who require a precise figure should test against their own worker heap configuration.
Mitigation
Upgrade to 3.1.0, where frames are decoded only after the handshake completes.
Users who cannot upgrade immediately should ensure that worker slot ports are reachable only from within the cluster, as the security model already recommends, and should enable `storm.messaging.netty.authentication` where the deployment permits it.
Credit
The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Weakness: CWE-789
Which versions are affected by CVE-2026-82435?
How do I fix CVE-2026-82435?
No fix has been published for CVE-2026-82435 yet. Limit exposure of the affected software until one is available.
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-2026-82435 being exploited?
There is no known exploitation of CVE-2026-82435 in the wild and no public exploit code.
Sources
Also known as GHSA-3mpj-29mm-p7wr.