---
id: "CVE-2026-125749"
page: "https://infrastack.ai/live/CVE-2026-125749"
kind: "vulnerability"
aliases: ["CVE-2026-125749"]
title: "TaxHacker: authenticated users can modify other users' settings and data"
severity: "medium"
cvss: 4.2
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "TaxHacker", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["nextjs", "other", "self-hosted", "taxhacker"]
not_affected_if: ["no-open-signup", "single-user"]
published_at: "2026-11-10T16:17:20+00:00"
first_seen_at: "2026-11-10T16:22:34+00:00"
updated_at: "2026-11-10T16:23:44+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125749", "first_seen_at": "2026-11-10T16:22:34+00:00"}]
exploit_sources: []
---

# TaxHacker: authenticated users can modify other users' settings and data

Link for people: https://infrastack.ai/live/CVE-2026-125749 (this .md is for agents)

TaxHacker through 0.8.5 trusts a user ID supplied in a request, so a logged-in user can act on another user's records. An attacker can delete categories, clear transaction assignments, or alter LLM prompts belonging to a victim.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:TaxHacker affected range not listed fixed no fixed version listed

## How to check

- Check the installed TaxHacker version; versions through `0.8.5` are affected.
- Review `app/(app)/settings/actions.ts` for server actions that take a `userId` from the request instead of the session.

## Fix

- Move to a version later than `0.8.5`; the sources do not name the exact fixed version.

## Timeline

- 2026-11-10T16:22:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125749

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/taxhacker-through-0.8.5-idor-via-settings-server-actions-userid
- [fix] Patch: github.com https://github.com/vas3k/TaxHacker/commit/d84a912f3a06b141cc275bb07115a204e7f10128

## From the sources

TaxHacker through 0.8.5 contains an insecure direct object reference vulnerability in app/(app)/settings/actions.ts that allows authenticated users to modify other users' data by supplying an arbitrary userId. Attackers can invoke Server Actions like deleteCategoryAction or editFieldAction with a victim's UUID to delete categories, clear transaction assignments, or alter LLM prompts.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_