PyLoad vulnerable to unauthenticated traceback disclosure via global exception handler in WebUI

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

• CVE-2026-44226: 0.34% estimated exploitation activity in the next 30 days; percentile 27.10 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary pyload-ng WebUI returns full Python traceback details to clients on unhandled exceptions. Because /web/<path:filename is reachable without authentication and renders attacker-controlled template names, an unauthenticated user can reliably trigger a server exception (for example by requesting a non-existent template) and receive internal stack traces in the HTTP response. Details The issue is caused by the combination of: 1. Unauthenticated template-render route: - src/pyload/webui/app/blueprints/appblueprint.py:32-36 - @bp.route("/web/<path:filename", endpoint="web") - data = rendertemplate(filename) with user-controlled filename - no @loginrequired(...) on this route 2. Global exception handler exposes traceback to response: - src/pyload/webui/app/handlers.py:14-27 - tb = traceback.formatexc() - messages.extend(tb.split('\n')) - returned in rendered error page for all exceptions 3. Error page renders all messages: -…

Published by the source

6 May 2026, 17:54 UTC

Last modified by the source

13 Jul 2026, 16:43 UTC

Source last checked

26 Oct 2026, 13:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-c3gc-9pf2-84gg

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-c3gc-9pf2-84gg

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# Patch Next advisory brief: CVE-2026-44226

Advisory: PyLoad vulnerable to unauthenticated traceback disclosure via global exception handler in WebUI
IDs: CVE-2026-44226, GHSA-c3gc-9pf2-84gg
Record: https://patchnext.com/advisories/cve-2026-44226 (revision 2, source checked 26 Oct 2026, 13:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: pyload-ng 0.5.0b3.dev100. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI pyload-ng: affected < 0.5.0b3.dev100; fixed in 0.5.0b3.dev100

## Suggested inspection (read-only)
- `python -m pip show pyload-ng`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pyload-ng.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-c3gc-9pf2-84gg (OSV record GHSA-c3gc-9pf2-84gg lists affected ranges: PyPI pyload-ng >=0 <0.5.0b3.dev100 (fixed))
- Verified: https://github.com/advisories/GHSA-c3gc-9pf2-84gg (GitHub-reviewed advisory GHSA-c3gc-9pf2-84gg lists affected ranges: PyPI pyload-ng >=0 <0.5.0b3.dev100)

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