Answer in brief
CVE-2026-48737 records a Medium severity (CVSS 4.9) vulnerability in pyLoad: SSRF guard bypass via IPv6 6to4/NAT64 transition wrappers of internal IPs. The current sources do not mark it as known exploited. The current feed maps pyload/pyload (generic), pyload-ng (pip). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps pyload/pyload (generic), pyload-ng (pip). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| pyload/pyloadgeneric | < 0.5.0b3.dev101 | Not reported |
| pyload-ngpip | <=0.5.0b3.dev100 | Not reported |
Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 9, 2026
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.
Quoted source text, attributed separately from HOL analysis.