Critical severity · published Oct 2, 2026
CVE-2026-103877
Apache Directory LDAP API: Unsafe loading of Java code from LDAP schema elements
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
Deserialization of Untrusted Data vulnerability in Apache Directory LDAP API.
A rogue/compromised LDAP server (or pre-TLS MITM) can answer a client's loadSchema() subschema search with a schema object that contains a serialized Java class, allowing some potential RCE.
This issue affects Apache Directory LDAP API: from 2.1.0 before 2.1.9.
Users are recommended to upgrade to version 2.1.9, which fixes the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% 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
2.1.0 before 2.1.9 · source: vendor
Affected product
AD
Apache Directory LDAP API
Apache Software Foundation
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103877
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103877
vendor-advisory
https://lists.apache.org/thread.html/sys8l881blqfgoc3o724jl32bmjl8pvw
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