High severity · published Jun 1, 2026
CVE-2026-35563
Apache Directory LDAP API: LDAP client implementation does not verify if the server certificate matches the intended LDAP hostname
8.5
CVSS
0.2%
EPSS
No
On KEV
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
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AD
Apache Directory LDAP API · Apache Software Foundation
2.0.0 through 2.1.7 · source: vendor
DL
Directory Ldap Api · Apache
2.0.0 before 2.1.7 · source: NVD
Affected product
AD
Apache Directory LDAP API
Apache Software Foundation
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35563
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-35563
Mailing List
https://lists.apache.org/thread/5rc2nzqxp1m9wknyf93r8dnp46fhc1nn
Mailing List
http://www.openwall.com/lists/oss-security/2026/06/01/2
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