CVE-2026-44183

Cleanuparr: X-Forwarded-For leftmost parsing allows remote unauthenticated admin takeover when reverse-proxy mode is enabled

Published May 12, 2026 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
Description
Cleanuparr is a tool for automating the cleanup of unwanted or blocked files in Sonarr, Radarr, and supported download clients like qBittorrent. Prior to 2.9.10, TrustedNetworkAuthenticationHandler.ResolveClientIp parses the leftmost entry of the X-Forwarded-For header as the client IP. That entry is attacker-controlled — X-Forwarded-For is append-only, so the leftmost value is whatever the original HTTP client claimed. By sending a spoofed local IP in the header, an unauthenticated remote attacker passes the trusted-network check and is logged in as the Cleanuparr administrator. This vulnerability is fixed in 2.9.10.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Cleanuparr
Cleanuparr cleanuparr
Vendors & Products Cleanuparr
Cleanuparr cleanuparr
Type Values Removed Values Added
Description Cleanuparr is a tool for automating the cleanup of unwanted or blocked files in Sonarr, Radarr, and supported download clients like qBittorrent. Prior to 2.9.10, TrustedNetworkAuthenticationHandler.ResolveClientIp parses the leftmost entry of the X-Forwarded-For header as the client IP. That entry is attacker-controlled — X-Forwarded-For is append-only, so the leftmost value is whatever the original HTTP client claimed. By sending a spoofed local IP in the header, an unauthenticated remote attacker passes the trusted-network check and is logged in as the Cleanuparr administrator. This vulnerability is fixed in 2.9.10.
Title Cleanuparr: X-Forwarded-For leftmost parsing allows remote unauthenticated admin takeover when reverse-proxy mode is enabled
Weaknesses CWE-290
CWE-348
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 13, 2026, 2:40 PM
Reserved
May 5, 2026, 2:39 PM
Status
Deferred
Published
May 12, 2026, 6:17 PM
Modified
Jun 17, 2026, 10:50 AM