5.4Medium

CVE-2026-86256

wger before 2.6 (affected versions <= 2.5.0) contains an open redirect vulnerability in the trainer_login view (wger/core/views/user.py). After a trainer enters impersonation mode, the view redirects to the user-supplied 'next' GET parameter via HttpResponseRedirect() without validating it with url_has_allowed_host_and_scheme(). An attacker who delivers a crafted link to an authenticated trainer can redirect the trainer's browser to an attacker-controlled domain, enabling phishing and leaking the wger URL structure (including the impersonated user's user_pk) via the Referer header.

What this means for your business

  • An attacker can use it remotely, over a network, with an ordinary user login, but only after tricking someone into an action such as opening a file or a link.
  • FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 7% of all known flaws.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
5.4 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CVSS v4
5.1
Weakness
CWE-601
Assigned by
disclosure@vulncheck.com

Dates

Published
2026-09-06
Last modified
2026-09-09
Sources
NVD

References