CVE-2026-103877
UnknownSummary
Deserialization of Untrusted Data vulnerability in Apache Directory LDAP API. A rogue or compromised LDAP server (or a pre-TLS MITM) can answer a client's loadSchema() subschema search with a schema object containing a serialized Java class, potentially allowing RCE. This issue affects versions from 2.1.0 before 2.1.9.
Risk Assessment
An attacker could achieve remote code execution in the LDAP client application, potentially leading to full system compromise. The risk is especially high in environments connecting to untrusted LDAP servers or exposed to MITM attacks.
Recommendation
Upgrade Apache Directory LDAP API to version 2.1.9, which fixes the issue. Until then, avoid connecting to untrusted LDAP servers and enforce TLS encryption.
Other vulnerabilities in Apache Directory LDAP API
See all- CVE-2026-103885Unknown
Asymmetric Resource Consumption vulnerability in Apache Directory LDAP API. An LDAP server using the LDAP API (like Apache DS) may consume 100% of a CPU core indefinitely when processing some badly crafted Telephone Numbers. This issue affects versions from 2.1.0 before 2.1.9. Users are recommended to upgrade to version 2.1.9.
- CVE-2026-103880Unknown
Asymmetric Resource Consumption vulnerability in Apache Directory LDAP API. Storing a password using the bcrypt algorithm with a high force like 30 in an LDAP server that supports this algorithm will cause the server CPU to run for hours checking the credentials. A bounded cost should be enforced to avoid a server DoS. This issue affects versions from 2.1.0 before 2.1.9. Users are recommended to upgrade to version 2.1.9.
- CVE-2026-103878Unknown
Cleartext transmission of sensitive information vulnerability in Apache Directory LDAP API. A StartTLS extended operation started after a Search request has been sent can lead to receive data in plain text before the TLS Handshake has been completed. This issue affects versions from 2.1.0 before 2.1.9. Users are recommended to upgrade to version 2.1.9.
- CVE-2026-103552Unknown
Stack Overflow vulnerability in Apache Directory LDAP API. Before binding, a client can send a deeply nested search filter that overflows the stack in the server's decoder. This issue affects versions from 1.2.0 before 1.2.9.
- CVE-2026-102731Unknown
Memory allocation with excessive size value vulnerability in Apache Directory LDAP API. A malicious peer (or a MITM) can send a small BER-encoded response causing a large memory allocation before any data is received, leading to OutOfMemoryError and denial of service. This issue affects versions from 1.2.0 before 1.2.9.
- CVE-2015-3250High
Apache Directory LDAP API before version 1.0.0-M31 allows attackers to conduct timing attacks via unspecified vectors.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS