# CVE-2026-40353: wger: Stored XSS via Unescaped License Attribution Fields

> An authenticated user can inject malicious JavaScript into license fields, leading to stored XSS that executes in other users' browsers.

- **Severity:** Medium 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Apr 2026
- **Updated:** 20 Apr 2026
- **Also known as:** GHSA-6f54-qjvm-wwq3, PYSEC-2026-3419

## What is CVE-2026-40353?

CVE-2026-40353 is a medium-severity cross-site scripting vulnerability in wger-project wger, published on 17 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

wger is a free, open-source workout and fitness manager. In versions 2.5 and below, the attribution_link property in AbstractLicenseModel constructs HTML by directly interpolating user-controlled license fields (such as license_author) without escaping, and templates render the result using Django's |safe filter. An authenticated user can create an ingredient with a malicious license_author value containing JavaScript, which executes in the browser of any visitor viewing the ingredient page, resulting in stored XSS. This issue has been fixed in version 2.5.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-40353?

3 open source packages ship an affected version, including wger. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `wger` | PyPI | All versions to 2.4 | None |
| `wger` | PyPI | All versions to 2.4 | None |
| `wger` | PyPI | All versions to 2.4 | None |

Products: Wger Wger.

## How do I fix CVE-2026-40353?

No fix has been published for CVE-2026-40353 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40353 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40353 exists.

## Other vulnerabilities in wger-project wger

- [CVE-2022-2650](https://insights.sbomify.com/CVE-2022-2650/): Improper Restriction of Excessive Authentication Attempts in wger-project/wger (high 7.8)
- [CVE-2026-40474](https://insights.sbomify.com/CVE-2026-40474/): wger has Broken Access Control in the Global Gym Configuration Update Endpoint (high 7.6)
- [CVE-2026-27835](https://insights.sbomify.com/CVE-2026-27835/): wger: IDOR in RepetitionsConfig and MaxRepetitionsConfig API leak other users' workout data (medium 4.3)
- [CVE-2026-27839](https://insights.sbomify.com/CVE-2026-27839/): wger: IDOR in nutritional_values endpoints exposes private dietary data via direct ORM lookup (medium 4.3)
- [CVE-2026-27838](https://insights.sbomify.com/CVE-2026-27838/): wger: IDOR via user-unscoped cache keys on routine API actions exposes workout data (low 3.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40353 and fix it if it is affected.

What it is: CVE-2026-40353 is a medium-severity cross-site scripting vulnerability in wger-project wger, published on 17 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40353 exists.

Affected packages and fixed versions:
- wger (PyPI): affected all versions up to 2.4; no fix listed
- wger (PyPI): affected all versions up to 2.4; no fix listed
- wger (PyPI): affected all versions up to 2.4; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-40353/ (Markdown: https://insights.sbomify.com/CVE-2026-40353/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40353
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40353
- OSV: https://osv.dev/vulnerability/CVE-2026-40353

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40353/
Summaries are generated and may contain mistakes; the official description above is the record.