---
id: "CVE-2026-15723"
kind: "vulnerability"
aliases: ["CVE-2026-15723"]
title: "GitLab CE/EE: SAML and LDAP auto-linking lets users take over LDAP accounts"
severity: "high"
cvss: 8.2
epss: 0.00334
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["gitlab", "infrastructure", "ldap", "saml", "self-hosted"]
not_affected_if: ["default-config", "managed-hosting"]
published_at: "2026-10-22T01:16:59+00:00"
first_seen_at: "2026-10-23T21:57:30+00:00"
updated_at: "2026-10-25T03:03:46+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-15723", "first_seen_at": "2026-10-23T21:57:30+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-15723", "first_seen_at": "2026-10-24T07:15:52+00:00"}]
---

# GitLab CE/EE: SAML and LDAP auto-linking lets users take over LDAP accounts

When OmniAuth SAML and LDAP auto-linking are both enabled, an authenticated GitLab user can take over an existing LDAP-backed account. The flaw is improper input sanitization in the LDAP email lookup used during OmniAuth identity linking, and no action from the victim is needed.

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

## How to check

- Run `grep -i -A3 'omniauth' /etc/gitlab/gitlab.rb` and check whether SAML is enabled.
- Check `gitlab.rb` for LDAP auto-linking settings (`auto_link_ldap_user` or equivalent) being enabled.
- Check the installed version with `gitlab-rake gitlab:env:info` and compare against the fixed versions.

## Fix

- Upgrade GitLab CE/EE to `19.3.6`, `19.4.3`, or `19.5.1` depending on the release line you run.
- If you cannot upgrade, disable OmniAuth SAML or LDAP auto-linking until the upgrade is applied.

## Timeline

- 2026-10-23T21:57:30+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-15723
- 2026-10-24T07:15:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-15723

## From the sources

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 10.1 before 19.3.6, 19.4 before 19.4.3, and 19.5 before 19.5.1 that, when OmniAuth SAML and LDAP auto-linking were both enabled, an authenticated user could have taken over an existing LDAP-backed account without any interaction from the targeted user, due to improper input sanitization in the LDAP email lookup path used during OmniAuth identity linking.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_