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Fencer Intel
high 7.8

CVE-2026-82429 json

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

published last mo. modified last mo. also EUVD-2026-77528

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

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.

Patch / fix

  • Apache Software Foundation Apache Storm Worker Launcher 3.1.0

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Apache Software Foundation Apache Storm Worker Launcher

Classification

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

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.