CVE-2026-82435
CVE-2026-82435 is a CWE-789 vulnerability. O3 Security confirms whether CVE-2026-82435 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
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.…
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-82435.
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-82435 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-82435 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-82435. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-82435 in your dependencies?
O3 detects CVE-2026-82435 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.