CVE-2026-42313

Published May 11, 2026

Last updated a month ago

CVSS high 8.3

Overview

Description
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.
Source
security-advisories@github.com
NVD status
Analyzed
Products
pyload-ng

Risk scores

CVSS 3.1

Type
Secondary
Base score
8.3
Impact score
5.5
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
Severity
HIGH

Weaknesses

security-advisories@github.com
CWE-441

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev100, when passing a folder name in the set_package_data() API function call inside the data object with key "_folder", there is no sanitization at all, allowing a user with Perms.MODIFY to specify arbitrary directories as download locations for a package. This vulnerability is fixed in 0.5.0b3.dev100.•CVE-2026-42315
  2. pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev100, package folder names are sanitized using insufficient string replacement. The pattern ....// becomes .._ after replacement (partial removal), leaving .. which can be exploited when the path is later resolved by the OS. This vulnerability is fixed in 0.5.0b3.dev100.•CVE-2026-42314
  3. 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 option ("general", "ssl_verify") is not on that allowlist. Any authenticated user with the non-admin SETTINGS permission can set general.ssl_verify = off, and every subsequent outbound pycurl request is made with SSL_VERIFYPEER=0 and SSL_VERIFYHOST=0 — TLS peer and hostname verification are fully disabled. An on-path attacker can then present forged certificates for any hostname pyload fetches. 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.•CVE-2026-42312
  4. pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev98, the set_session_cookie_secure before_request handler in src/pyload/webui/app/__init__.py reads the X-Forwarded-Proto header from any HTTP request without validating that the request originates from a trusted proxy, then mutates the global Flask configuration SESSION_COOKIE_SECURE on every request. Because pyLoad uses the multi-threaded Cheroot WSGI server (request_queue_size=512), this creates a race condition where an attacker's request can influence the Secure flag on other users' session cookies — either downgrading cookie security behind a TLS proxy or causing a session denial-of-service on plain HTTP deployments. This vulnerability is fixed in 0.5.0b3.dev98.•CVE-2026-40594
  5. pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev97, the _safe_extractall() function in src/pyload/plugins/extractors/UnTar.py uses os.path.commonprefix() for its path traversal check, which performs character-level string comparison rather than path-level comparison. This allows a specially crafted tar archive to write files outside the intended extraction directory. The correct function os.path.commonpath() was added to the codebase in the CVE-2026-32808 fix (commit 5f4f0fa) but was never applied to _safe_extractall(), making this an incomplete fix. This vulnerability is fixed in 0.5.0b3.dev97.•CVE-2026-35592

References

Sources include official advisories and independent security research.