wger has Stored XSS via Unescaped License Attribution Fields

Exploitation

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

CVSS 4.0

5.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N · score source

EPSS

• CVE-2026-40353: 0.21% estimated exploitation activity in the next 30 days; percentile 10.88 (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.

Stored XSS via Unescaped License Attribution Fields Summary The AbstractLicenseModel.attributionlink property in wger/utils/models.py constructs HTML strings by directly interpolating user-controlled fields (licenseauthor, licensetitle, licenseobjecturl, licenseauthorurl, licensederivativesourceurl) without any escaping. The resulting HTML is rendered in the ingredient view template using Django's |safe filter, which disables auto-escaping. An authenticated user can create an ingredient with a malicious licenseauthor value containing JavaScript, which executes when any user (including unauthenticated visitors) views the ingredient page. Severity High (CVSS 3.1: ~7.6) - Low-privilege attacker (any authenticated non-temporary user) - Stored XSS — persists in database - Triggers on a public page (no authentication needed to view) - Can steal session cookies, perform actions as other users, redirect to phishing CWE CWE-79: Improper Neutralization of Input During Web Page Generation…

Published by the source

16 Apr 2026, 01:37 UTC

Last modified by the source

13 Jul 2026, 16:42 UTC

Source last checked

26 Oct 2026, 13:40 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-6f54-qjvm-wwq3

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-6f54-qjvm-wwq3

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# Patch Next advisory brief: CVE-2026-40353

Advisory: wger has Stored XSS via Unescaped License Attribution Fields
IDs: CVE-2026-40353, GHSA-6f54-qjvm-wwq3
Record: https://patchnext.com/advisories/cve-2026-40353 (revision 3, source checked 26 Oct 2026, 13:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI wger: affected <= 2.4

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on wger.
- 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-6f54-qjvm-wwq3 (OSV record GHSA-6f54-qjvm-wwq3 lists affected ranges: PyPI wger >=0 <=2.4)
- Verified: https://github.com/advisories/GHSA-6f54-qjvm-wwq3 (GitHub-reviewed advisory GHSA-6f54-qjvm-wwq3 lists affected ranges: PyPI wger >=0 <=2.4)

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