High severity · published Oct 2, 2026
CVE-2026-103878
Apache Directory LDAP API: Injection of plaintext responses during StartTLS
7.5
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 10% 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-2026-103878
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103878
vendor-advisory
https://lists.apache.org/thread.html/d98f9w01nd3zmkwrr21y0l9kdr9jpty9
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