CVE-2025-7346 is a high-severity (CVSS 7.5) CWE-281 vulnerability in pyload-ng. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
pyLoad is vulnerable to attacks that bypass localhost restrictions, enabling the creation of arbitrary packages
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-7346.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
pyload-ngReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Any unauthenticated attacker can bypass the localhost restrictions posed by the application and utilize this to create arbitrary packages.
Details
Any unauthenticated attacker can bypass the localhost restrictions posed by the application and utilize this to create arbitrary packages. This is done by changing the Host header to the value of 127.0.0.1:9666.
PoC
The application has middleware that prevents access to several routes by checking whether the Host header has a specific value. We bypassed this restriction.
#: decorator
def local_check(func):
@wraps(func)
def wrapper(*args, **kwargs):
remote_addr = flask.request.environ.get("REMOTE_ADDR", "0")
http_host = flask.request.environ.get("HTTP_HOST", "0")
if remote_addr in ("127.0.0.1", "::ffff:127.0.0.1", "::1", "localhost") or http_host in (
"127.0.0.1:9666",
"[::1]:9666",
):
return func(*args, **kwargs)
else:
return "Forbidden", 403
return wrapper
Below we see that the '/flash/add' endpoint uses the middleware above.
@bp.route("/flash/add", methods=["POST"], endpoint="add")
@local_check
def add():
Notice how we are not authorized to access this endpoint when sending a request.
However, if we set the Host header to be 127.0.0.1:9666, we notice the request returns success.
Checking the front end as an admin, we now see that this did indeed succeed.
Impact
An unauthenticated user can perform actions that should only be available to authenticated users.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pyload-ng | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyload-ng, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of pyload-ng for CVE-2025-7346. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2025-7346 in your dependencies?
Find it across PyPI, including transitive dependencies.