CVE-2026-48737
- Source
- https://cve.org/CVERecord?id=CVE-2026-48737
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48737.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-48737
- Aliases
- Published
- 2026-09-15T14:40:27Z
- Modified
- 2026-09-18T03:30:15Z
- Severity
-
- 4.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:L CVSS Calculator
- Summary
- pyLoad: SSRF guard bypass via IPv6 6to4/NAT64 transition wrappers of internal IPs
- Details
-
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.
- Database specific
{ "cna_assigner": "GitHub_M", "cwe_ids": [ "CWE-918" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48737.json", "unresolved_ranges": [ { "extracted_events": [ { "fixed": "0.5.0b3.dev101" } ], "source": "AFFECTED_FIELD" }, { "extracted_events": [ { "introduced": "3.9" }, { "fixed": "3.11" } ], "source": "DESCRIPTION" } ] }- References