# CVE-2026-82429: Apache Storm Worker Launcher: Local Privilege Escalation to Root via a Time-of-Check Race in the Worker Launcher

> A local attacker can escalate privileges to root by exploiting a race condition in the Apache Storm worker launcher during directory permission updates.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** No
- **Published:** 14 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-qchc-32xg-c7w6

## What is CVE-2026-82429?

CVE-2026-82429 is a high-severity vulnerability in Apache Storm Worker Launcher, published on 14 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Description

The setuid-root `worker-launcher` binary adjusts ownership and permissions of worker directories by walking
the tree with FTS and calling `lchown` and `chmod` on each entry's full pathname while running with an
effective uid of 0. Both syscalls re-resolve the path at the time of the call, after FTS has classified the
entry, and the trees being walked are owned and writable by the untrusted topology user.

A tenant running code on a supervisor node could therefore replace an intermediate directory component with
a symbolic link between classification and the privileged operation, redirecting the root-owned `lchown` or
`chmod` at an arbitrary file on the host. The operation is repeatable at will, since crashing a worker
forces a relaunch and blob updates re-run the walk, so a failed attempt costs the attacker nothing.

This crosses the boundary that `supervisor.run.worker.as.user` and container isolation are intended to
enforce. It is the same defect class as the Hadoop container-executor issues from which this code derives.

Mitigation

Upgrade to 3.1.0, where the privileged walk operates on file descriptors it has already stat'd rather than
on pathnames re-resolved at call time.

Users who cannot upgrade immediately should not run untrusted topology code on supervisors configured with
`supervisor.run.worker.as.user`, since the launcher is the boundary being crossed. Note that the launcher
must be rebuilt and reinstalled after upgrading; replacing the Java artifacts alone is not sufficient.

Credit

The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2026-82429?


## How do I fix CVE-2026-82429?

No fix has been published for CVE-2026-82429 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82429 being exploited?

There is no known exploitation of CVE-2026-82429 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82429 and fix it if it is affected.

What it is: CVE-2026-82429 is a high-severity vulnerability in Apache Storm Worker Launcher, published on 14 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-82429 in the wild and no public exploit code.

Affected product: Apache Storm Worker Launcher. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82429/ (Markdown: https://insights.sbomify.com/CVE-2026-82429/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82429
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82429
- OSV: https://osv.dev/vulnerability/CVE-2026-82429

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82429/
Summaries are generated and may contain mistakes; the official description above is the record.