CVE-2026-81205 Overview
CVE-2026-81205 is an LDAP Injection vulnerability in the Drupal LDAP / Active Directory Integration contributed module. The flaw stems from improper neutralization of special elements used in Lightweight Directory Access Protocol (LDAP) queries [CWE-90]. It affects module versions from 0.0.0 through 2.2.1. A remote, unauthenticated attacker can craft input that alters the structure of LDAP queries executed by the module. Successful exploitation results in limited information disclosure from the connected directory service. The vulnerability requires no user interaction and is exploitable over the network.
Critical Impact
An unauthenticated attacker can manipulate LDAP queries against the connected Active Directory or LDAP backend, exposing directory information.
Affected Products
- Drupal LDAP / Active Directory Integration module
- Versions 0.0.0 through 2.2.1
- Drupal sites configured to bind against Active Directory or other LDAP servers via this module
Discovery Timeline
- 2026-09-02 - CVE-2026-81205 published to NVD
- 2026-09-02 - Last updated in NVD database
- Reference: Drupal Security Advisory SA-CONTRIB-2026-115
Technical Details for CVE-2026-81205
Vulnerability Analysis
The LDAP / Active Directory Integration module builds LDAP queries using user-controlled input without adequately escaping LDAP metacharacters. Characters such as *, (, ), \, and NUL bytes carry syntactic meaning inside LDAP search filters. When these characters pass unsanitized into a filter expression, the attacker can alter the logical structure of the query. This allows filter clauses to be broadened, bypassed, or redirected to enumerate directory attributes. The confidentiality impact is limited to information that the module's bind account can read from the directory. Integrity and availability of the directory service are not affected according to the published CVSS metrics.
Root Cause
The root cause is missing or incomplete escaping of LDAP special elements before concatenating attacker-controlled values into filter strings. This class of flaw is tracked as CWE-90: Improper Neutralization of Special Elements used in an LDAP Query. Safe implementations must escape input per RFC 4515 before it reaches the LDAP client library.
Attack Vector
The attack vector is network-based and requires no authentication or user interaction. An attacker submits crafted values to a Drupal endpoint that feeds parameters into an LDAP query, such as a login, user lookup, or search feature exposed by the module. The injected filter syntax modifies the query executed against the directory. See the Drupal Security Advisory for vendor-supplied exploitation context.
No verified proof-of-concept code is publicly available for CVE-2026-81205. The vulnerability manifests when unsanitized input reaches an LDAP search filter constructed by the affected module. Refer to the vendor advisory for technical specifics.
Detection Methods for CVE-2026-81205
Indicators of Compromise
- Web server access logs containing LDAP metacharacters such as *, (, ), or \ in parameters routed to authentication or user lookup endpoints of the Drupal LDAP module.
- Unusual spikes in LDAP search operations originating from the Drupal application service account.
- Directory server logs showing broad or malformed search filters, for example filters containing *)(objectClass=* patterns.
Detection Strategies
- Enable verbose LDAP query logging on the Drupal side and correlate query text with the originating HTTP request.
- Deploy web application firewall rules that flag LDAP special characters in parameters bound for user, mail, or uid fields.
- Review Drupal watchdog and PHP error logs for LDAP client errors triggered by malformed attacker input.
Monitoring Recommendations
- Alert on anomalous volume of LDAP search operations from the Drupal application account.
- Baseline expected LDAP filter shapes and alert on deviations such as wildcard-heavy filters.
- Monitor authentication endpoints for failed login patterns paired with LDAP filter metacharacters.
How to Mitigate CVE-2026-81205
Immediate Actions Required
- Upgrade the Drupal LDAP / Active Directory Integration module to a fixed release beyond 2.2.1 per the vendor advisory.
- Audit Drupal configuration to identify endpoints that accept user input feeding LDAP queries and restrict them where feasible.
- Rotate credentials of the LDAP bind account used by Drupal if exploitation is suspected.
Patch Information
Apply the patched module version referenced in the Drupal Security Advisory SA-CONTRIB-2026-115. Site maintainers should follow standard Drupal contributed module update procedures using composer update or the Update Manager.
Workarounds
- Restrict permissions of the LDAP bind account to the minimum directory subtree and attributes required.
- Place the Drupal site behind a WAF configured to reject LDAP filter metacharacters in relevant parameters.
- Temporarily disable the LDAP / Active Directory Integration module until the patched version is deployed.
# Update the contributed module to the patched release
composer update drupal/ldap --with-dependencies
drush updatedb
drush cache:rebuild
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
