---
id: "CVE-2026-129132"
page: "https://infrastack.ai/live/CVE-2026-129132"
kind: "vulnerability"
aliases: ["CVE-2026-129132"]
title: "MRBS: LDAP login filter lets crafted usernames bypass group restrictions"
severity: "medium"
cvss: 4.2
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "MRBS", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ldap", "mrbs", "package", "self-hosted"]
not_affected_if: ["mrbs-1.13.0-or-later", "non-ldap-auth"]
published_at: "2026-11-13T17:17:31+00:00"
first_seen_at: "2026-11-13T17:48:01+00:00"
updated_at: "2026-11-13T17:49:10+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-129132", "first_seen_at": "2026-11-13T17:48:01+00:00"}]
exploit_sources: []
---

# MRBS: LDAP login filter lets crafted usernames bypass group restrictions

Link for people: https://infrastack.ai/live/CVE-2026-129132 (this .md is for agents)

MRBS (Meeting Room Booking System) builds LDAP search filters from raw login usernames without escaping them. A user with valid directory credentials but outside the required group can submit a crafted username that makes the group check always true and gain access.

_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 installed MRBS version in the release files or `web/lib/MRBS/Auth/AuthLdap.php` and compare it with `1.13.0`
- Confirm LDAP authentication is enabled in the MRBS configuration (`unknown` if the sources do not name the setting)

## Fix

- MRBS: upgrade to `1.13.0` or later

## Timeline

- 2026-11-13T17:48:01+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-129132

## Documents

- [advisory] Vendor advisory: github.com https://github.com/meeting-room-booking-system/mrbs-code/security/advisories/GHSA-r543-f38c-cq6v
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/mrbs-before-1.13.0-ldap-injection-via-authldap-php-authentication-filter
- [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 an LDAP injection vulnerability in web/lib/MRBS/Auth/AuthLdap.php that interpolates unescaped login usernames into DN search and group-membership filters. Attackers with valid directory credentials outside the required group can submit crafted usernames that make the group filter always true, bypassing access restrictions.

---

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