SECURELYN

CVE-2026-103877

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.

Scores

9.8
CVSS 9.8 out of 10, critical severity.
0.6%
EPSS 0.6% chance of exploitation in the next 30 days.

The facts

Published
2 October 2026
Last changed
7 October 2026
NVD status
Deferred
Severity
Critical, CVSS 9.8 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
0.6% chance of exploitation activity in the next 30 days (percentile 46).

Is there a Securelyn advisory?

Not yet. Securelyn writes plain-English advisories for the flaws that matter most to businesses. Subscribe to the digest to hear about them.

References