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🐍 PyPI
Not in CISA KEV
HIGH severity

CVE-2025-7346 pyload-ng

HIGHFix: pyload/pyload@f4e2d12

CVE-2025-7346 is a high-severity (CVSS 7.5) CWE-281 vulnerability in pyload-ng. No vendor fix is recorded yet; mitigation options are listed below.

pyLoad is vulnerable to attacks that bypass localhost restrictions, enabling the creation of arbitrary packages

Also known asPYSEC-2026-1822
Published
Jul 8, 2025
Updated
Jul 7, 2026
Affected
1 pkg
Patched
See advisory
Exploits
None indexed
Exploitation data as of Sep 20, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs25th percentile — riskier than 25% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2025-7346 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐍pyload-ng

Real-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.

https://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L21-L36

#: 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.

https://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L56-L58C11

@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. image

However, if we set the Host header to be 127.0.0.1:9666, we notice the request returns success. image

Checking the front end as an admin, we now see that this did indeed succeed. image

Impact

An unauthenticated user can perform actions that should only be available to authenticated users.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
🐍PyPIpyload-ngall versionsNo fix

Detection & mitigation playbook

Open-source dependency
  1. Detect

    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.

  2. Remediation status

    No patched version of pyload-ng has shipped for CVE-2025-7346 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-7346 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2025-7346. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### 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. https://github.com/pyload/pyload/blob/4159a1191ec4
O3 Security · Impact-Aware SCA

Is CVE-2025-7346 in your dependencies?

O3 Security finds CVE-2025-7346 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.