CVE-2026-48737
MediumCVSS 4.9Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
In pyLoad prior to 0.5.0b3.dev101, is_global_address in src/pyload/core/utils/web/check.py relies on Python's global-address classification without examining IPv4 destinations embedded in 6to4 or NAT64 IPv6 addresses. A low-privileged user can submit an IPv6 literal through parse_urls to the pre-resolution is_global_host guard, and curl resolves hostnames before the same vulnerable check is applied, permitting connections to embedded loopback, private, CGNAT, or link-local IPv4 addresses.
Risk Assessment
Successful exploitation can enable internal-network reconnaissance, timing-based confirmation, limited service disruption, or cloud metadata disclosure where the wrapped address is routable.
Recommendation
Update pyLoad to version 0.5.0b3.dev101, where the issue is fixed.
Other vulnerabilities in pyLoad
See all- CVE-2026-42315High
In pyLoad prior to version 0.5.0b3.dev100, there is a vulnerability that allows a user with Perms.MODIFY to specify arbitrary directories as download locations for a package through the set_package_data() API function. The lack of sanitization in the '_folder' key enables this action.
- CVE-2026-42313High
In pyLoad prior to version 0.5.0b3.dev100, the set_config_value() API method improperly managed security-sensitive options, allowing authenticated users with SETTINGS permission to enable proxying and route traffic through a host they control.
- CVE-2026-35459Critical
pyLoad in version 0.5.0b3.dev96 and earlier has an SSRF vulnerability. The fix for CVE-2026-33992 added IP validation, but pycurl automatically follows HTTP redirects and redirect targets are not validated. An authenticated user with ADD permission can bypass the SSRF filter by using a URL that redirects to an internal address.
- CVE-2026-48987Medium
In pyLoad prior to 0.5.0b3.dev101, EventManager in src/pyload/core/managers/event_manager.py appends a Client object to the clients list for each unique uuid submitted to the authenticated getEvents API endpoint, but get_events does not invoke the available clean method to remove inactive clients. An authenticated user can repeatedly submit unique UUID values, causing retained client objects and process memory to grow without bound.
- CVE-2026-35187High
In pyLoad 0.5.0b3.dev96 and earlier, the parse_urls API function fetches arbitrary URLs server-side without validation. An authenticated user with ADD permission can read internal resources, local files (file://), and use gopher:// and dict:// protocols.
- CVE-2023-47890High
pyLoad 0.5.0 is vulnerable to unrestricted file upload, allowing an attacker to upload arbitrary files to the server without proper validation.
Original NVD description (English source)
pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev101, is_global_address in src/pyload/core/utils/web/check.py relies on Python's global-address classification without examining IPv4 destinations embedded in 6to4 or NAT64 IPv6 addresses. A low-privileged user can submit an IPv6 literal through parse_urls to the pre-resolution is_global_host guard. Because host_to_ip is pinned to AF_INET, that guard does not evaluate a hostname's AAAA result. Separately, curl resolves hostnames before the pycurl PREREQFUNC in src/pyload/core/network/http/http_request.py applies the same vulnerable is_global_address check to the actual connection address, so a transition-form AAAA result can be permitted even when it terminates at an embedded loopback, private, CGNAT, or link-local IPv4 address. Exploitation requires the pyLoad host to route the applicable transition mechanism, including 6to4 on affected Python 3.9 through 3.11 deployments or NAT64 on a network with a NAT64 gateway. Successful exploitation can enable internal-network reconnaissance, timing-based confirmation, limited service disruption, or cloud metadata disclosure where the wrapped address is routable. This issue is fixed in version 0.5.0b3.dev101.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS