---
id: "CVE-2026-129134"
page: "https://infrastack.ai/live/CVE-2026-129134"
kind: "vulnerability"
aliases: ["CVE-2026-129134"]
title: "MRBS: forged Host header poisons password reset links, enabling account takeover"
severity: "high"
cvss: 8.6
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "MRBS", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["mrbs", "package", "php", "self-hosted"]
not_affected_if: ["url-base-set"]
published_at: "2026-11-13T17:17:31+00:00"
first_seen_at: "2026-11-13T17:48:01+00:00"
updated_at: "2026-11-13T17:48:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-129134", "first_seen_at": "2026-11-13T17:48:01+00:00"}]
exploit_sources: []
---

# MRBS: forged Host header poisons password reset links, enabling account takeover

Link for people: https://infrastack.ai/live/CVE-2026-129134 (this .md is for agents)

MRBS (a meeting room booking system) before 1.13.0 builds password reset links from the request's Host header when $url_base is unset. An unauthenticated attacker can make a reset email point to their own host and capture the reset key when the victim opens it, taking over the account, including administrator accounts.

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

## Affected

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

## How to check

- Check the MRBS version in use; versions below `1.13.0` are in the affected range.
- Check whether `$url_base` is set in the MRBS configuration; it is unset in the affected case.

## Fix

- Upgrade MRBS to `1.13.0` or later.

## Timeline

- 2026-11-13T17:48:01+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-129134

## Documents

- [advisory] Vendor advisory: github.com https://github.com/meeting-room-booking-system/mrbs-code/security/advisories/GHSA-73cv-hx7f-9v27
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/mrbs-before-1.13.0-password-reset-poisoning-via-host-header-injection
- [fix] Patch: github.com https://github.com/meeting-room-booking-system/mrbs-code/commit/92f6f5610072ddb9e1b38074c410fc8be56947ed
- [fix] Release notes: github.com https://github.com/meeting-room-booking-system/mrbs-code/releases/tag/v1.13.0

## From the sources

MRBS before 1.13.0 contains a password reset poisoning vulnerability that allows unauthenticated attackers to redirect reset links by forging the Host header when $url_base is unset. Attackers can request a reset for a victim so AuthDb::notifyUser() emails a link pointing to their host, capturing the reset key when opened to take over accounts including administrators.

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