Auth bypass in Apache Software Foundation Storm Logviewer

CVE-2026-82437

Description The Logviewer offers `logs.users` and `logs.groups` so operators can control who may read log content. For daemon logs those settings were not applied: the access decision combined the "this is a daemon log" flag with the authorizer result in a way that discarded the authorizer's answer whenever the flag was set, and the daemon log page and download endpoints reached the handler without consulting an authorizer at all. Any user able to pass the configured servlet filter could therefore read `nimbus.log`, `supervisor.log` and the other daemon logs on every reachable node, which contain other tenants' topology names, owners and configuration fragments. The same advisory covers the log listing endpoints, which accepted a user argument and never applied it, so `/listLogs` and `/searchLogs` returned every tenant's topology and worker log file names regardless of the caller. That part is metadata only. There was no configuration that closed either behaviour. Mitigation Upgrade to 3.1.0, where the daemon log paths evaluate the same configured user and group lists that the worker log paths already used, and the listing endpoints filter by the requesting user. Users who cannot upgrade immediately should place the Logviewer behind a reverse proxy that restricts the daemon log endpoints, and should treat daemon log content as readable by any filter-authenticated user. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-82437?
CVE-2026-82437 is a medium-severity vulnerability in Apache Software Foundation Storm Logviewer, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-09-14.
How severe is CVE-2026-82437?
Medium severity. CVSS v3 base score is 4.3 out of 10.