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Fencer Intel
critical 9.8

CVE-2026-103877 json

Apache Directory LDAP API: Unsafe loading of Java code from LDAP schema elements

published last mo. modified last mo. also EUVD-2026-91361

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

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.

Patch / fix

  • Apache Software Foundation Apache Directory LDAP API 2.1.9

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-103877 updated cvss 8.1

org.apache.directory.api/api-ldap-client-api: Apache Directory LDAP API: Remote code execution via untrusted Java object deserialization

  • Red Hat Fuse 7 api-ldap-client-api 1.0.0
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
last mo.

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Apache Software Foundation Apache Directory LDAP API

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.