Is CVE-2026-86256 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-86256 being exploited in the wild.

How severe is CVE-2026-86256?

Medium severity, with a CVSS score of 5.4, published 6 September 2026.

Which products and versions are affected?

wger (PyPI) ECOSYSTEM:introduced=0,fixed=2.6.

Is there a fix for CVE-2026-86256?

Yes. wger (PyPI): upgrade to 2.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-86256 attacked?

It is attacked over the network.

Am I affected by CVE-2026-86256?

Check whether you run wger (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-86256: wger trainer_login open redirect in next parameter

CVE-2026-86256 · Severity: medium · CVSS 5.4 · Published 2026-09-06

wger is a web-based fitness and gym management application used by trainers to manage client workouts and impersonation sessions. The trainer_login view fails to validate the redirect destination after a trainer enables impersonation mode, allowing an attacker to redirect the trainer to a malicious website. This can enable phishing attacks and leak sensitive information such as the impersonated user's ID through the browser's referrer header.

Technologies: wger (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2026-86256 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-86256 being exploited in the wild.
How severe is CVE-2026-86256?: Medium severity, with a CVSS score of 5.4, published 6 September 2026.
Which products and versions are affected?: wger (PyPI) ECOSYSTEM:introduced=0,fixed=2.6.
Is there a fix for CVE-2026-86256?: Yes. wger (PyPI): upgrade to 2.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-86256 attacked?: It is attacked over the network.
Am I affected by CVE-2026-86256?: Check whether you run wger (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

wger (PyPI): upgrade to 2.6 or later
```
pip install "wger>=2.6"
```

Technical details

The vulnerability is an open redirect (CWE-601) in the trainer_login view (wger/core/views/user.py, line 203) that fails to validate the 'next' GET parameter before redirecting via HttpResponseRedirect(). The vulnerable code performs no call to Django's url_has_allowed_host_and_scheme() function to ensure the redirect target is on the same host. An authenticated trainer with gym trainer permissions can be exploited by clicking a crafted link (e.g., /en/user/2/trainer-login?next=https://evil.example/steal). When the trainer enters impersonation mode, the view redirects to the attacker-controlled URL, leaking the impersonated user's user_pk via the Referer header. The fix involves adding host and scheme validation before the redirect. Patched in wger 2.6 and later.

Affected products

wger wger <= 2.5.0

Identifiers

CVE-2026-86256
GHSA-vqv8-j3mj-wjxj

Timeline

2026-04-28: disclosed: GitHub Security Advisory published
2026-09-06: advisory: NVD and public advisory published
2026: patched: Fixed in wger 2.6 and later

References

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