CVE-2026-35563 Apache Directory LDAP API lacks server certificate verification for LDAP hostnames
Attackers can impersonate LDAP servers via MITM due to missing hostname verification, allowing data interception or modification.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-35563?
CVE-2026-35563 is a high-severity vulnerability in Apache Directory LDAP API, published on 1 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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
Weakness: CWE-297
Which versions are affected by CVE-2026-35563?
2 open source packages ship an affected version, including org.apache.directory.api:api-ldap-client-api. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.apache.directory.api:api-ldap-client-api Maven | From 2.0.0 | 2.1.8 |
org.apache.directory.api:api-ldap-client-api Maven | From 2.0.0 | 2.1.8 |
Products include Apache Directory Ldap Api.
How do I fix CVE-2026-35563?
Upgrade org.apache.directory.api:api-ldap-client-api to 2.1.8 or later.
Is CVE-2026-35563 being exploited?
There is no known exploitation of CVE-2026-35563 in the wild and no public exploit code.
Other vulnerabilities in Apache Directory LDAP API
Sources
Also known as CLEANSTART-2026-EU32419, DEBIAN-CVE-2026-35563, GHSA-85rw-g4f4-jprr, UBUNTU-CVE-2026-35563.