CVE-2026-103878: Apache Directory LDAP API: Injection of plaintext responses during StartTLS
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.2%
EPSS score, percentile 10.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 7.5 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- from 2.1.0 to before 2.1.9
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 2.1.0 to before 2.1.9 |
Versions not listed are: unaffected.
Source: CVE List, as of . About the data.
About this vulnerability
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 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 i…
Summary: CVE record, as of .
- CISA has not added CVE-2026-103878 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 2 Oct 2026.
- The CVE record carries a CVSS v3.1 base score of 7.5 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 10.2), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable yes, technical impact partial.
- The credits in the CVE record name Anthropic (Claude) as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
Apache Directory LDAP API: Injection of plaintext responses during StartTLS
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 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.
Source: CVE List, as of . About the data.
Weakness
CWE-345
- CWE-345: (Insufficient Verification of Data Authenticity)
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
Known exploited Apache vulnerabilities
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- CVE-2026-34197: Apache ActiveMQ Improper Input Validation Vulnerability
- CVE-2024-38475: Apache HTTP Server Improper Escaping of Output Vulnerability
- CVE-2025-24813: Apache Tomcat Path Equivalence Vulnerability