high CVSS 8.3

CVE-2026-42313·Python vulnerability

pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev100, the set_config_value() API method (@permission(Perms.SETTINGS)) in src/pyload/core/api/__init__.py gates security-sensitive options behind a hand-maintained allowlist ADMIN_ONLY_CORE_OPTIONS. The allowlist contains ("proxy", "username") and ("proxy", "password") — which protect the proxy credentials — but it does not include ("proxy", "enabled"), ("proxy", "host"), ("proxy", "port"), or ("proxy", "type"). Any authenticated user with the non-admin SETTINGS permission can enable proxying and point pyload at any host they control. From that point, every outbound download, captcha fetch, update check, and plugin HTTP call is transparently routed through the attacker. This is a direct continuation of the fix family CVE-2026-33509 / CVE-2026-35463 / CVE-2026-35464 / CVE-2026-35586, each of which patched a different missed option in the same allowlist. This vulnerability is fixed in 0.5.0b3.dev100.

Severity
high
Software
Python
Fixed in
0.5.0b3.dev100
Published
2026-05-11

Affected versions

Until: 0.5.0b3.dev100

Fixed in: 0.5.0b3.dev100

How to fix this CVE

Upgrade pyLoad to version 0.5.0b3.dev100 or later to patch incomplete proxy configuration allowlist validation. Non-admin users with SETTINGS permission can currently manipulate proxy settings to route all outbound traffic through attacker-controlled hosts. Update your Python environment immediately to prevent man-in-the-middle attacks on downloads, captcha requests, and plugin communications.

sudo dnf check-update python3 && sudo dnf upgrade python3

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed pyLoad version: pip show pyload | grep Version
  2. Verify if pyLoad is running: systemctl status pyload or ps aux | grep pyload
  3. Review pyLoad configuration file for proxy settings: cat ~/.config/pyload/settings.cfg | grep -i proxy
  4. Inspect recent access logs for unauthorized proxy configuration changes: grep 'set_config_value' /var/log/pyload/*.log or check application logs for SETTINGS permission API calls
  5. Confirm the fix: pip show pyload | grep -q '0.5.0b3.dev100' && echo 'Patched' || echo 'Vulnerable'

FAQ

What is CVE-2026-42313?

This vulnerability allows non-admin users with SETTINGS permission in pyLoad to reconfigure proxy settings (host, port, type, enabled status) that were not properly restricted, enabling them to redirect all outbound connections through attacker-controlled infrastructure for traffic interception.

Is CVE-2026-42313 being actively exploited?

No, this vulnerability is not currently listed in CISA's Known Exploited Vulnerabilities catalog, and no public exploits are available. However, the attack is straightforward and requires only basic network access.

What versions of pyLoad are affected by CVE-2026-42313?

All versions prior to 0.5.0b3.dev100 are vulnerable. This includes all stable releases and development builds released before this patch.

How do I check if my server is vulnerable to CVE-2026-42313?

Run 'pip show pyload | grep Version' and verify the version number is 0.5.0b3.dev100 or higher. If it is lower, your installation is vulnerable.

Does Defensia detect CVE-2026-42313?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If pyLoad is installed on a monitored server, CVE-2026-42313 will appear in your dashboard with remediation steps.

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References

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