CVE-2026-35563

It was identified that the LDAP client implementation in version 2.1.7 does not verify if the server certificate matches the intended LDAP hostname. While the underlying code validates the certificate chain against a trusted authority, the absence of endpoint identification allows a valid certificate issued for an entirely unrelated host to be improperly accepted. This oversight leaves the connection highly vulnerable to server impersonation and complete connection compromise.

The root cause of this vulnerability lies in the incomplete TLS server identity verification within the LDAP client implementation.

The attacker requires MITM capability on the network to exploit this vulnerability. This attacker must be able to present a certificate trusted by the client's configured trust store.

The hostname verification has been enforced in the new version of the LDAP API

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35563.json",
    "cna_assigner": "apache",
    "cwe_ids": [
        "CWE-297"
    ],
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "2.0.0"
                },
                {
                    "last_affected": "2.1.7"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}

References

Affected packages

Git / github.com/apache/directory-ldap-api

Affected ranges

Type

GIT

Repo

https://github.com/apache/directory-ldap-api

Events

Introduced

763ad553749e59cfb12259c8f58a75aee3653d1a

Fixed

d57c39c7883ad554eef1bba1eee55cdd008775e3

Database specific

{
    "cpe": "cpe:2.3:a:apache:directory_ldap_api:*:*:*:*:*:*:*:*",
    "source": "CPE_RANGE",
    "extracted_events": [
        {
            "introduced": "2.0.0"
        },
        {
            "fixed": "2.1.7"
        }
    ]
}

Affected versions

2.*

2.0.0

2.0.1

2.0.2

2.1.0

2.1.1

2.1.2

2.1.3

2.1.4

2.1.5

2.1.6

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-35563.json"