CVE-2026-103878
Description
A flaw was found in the Apache Directory LDAP API. When a StartTLS operation is initiated after a search request has already been sent, the client can receive response data in cleartext before the Transport Layer Security (TLS) handshake completes. An attacker capable of intercepting network traffic can exploit this vulnerability to read sensitive directory data transmitted in plain text.
Statement
A moderate information disclosure flaw was found in the Apache Directory LDAP API, which is shipped in Red Hat JBoss Fuse 7 as the api-ldap-client-api Maven component. When a StartTLS extended operation is initiated after a search request has already been sent, the client can receive response data in cleartext before the TLS handshake completes. An attacker able to intercept network traffic between the LDAP client and server, such as an on-path man-in-the-middle attacker, could exploit this flaw to read sensitive directory data transmitted in plain text. Red Hat rates this flaw as moderate severity (CVSS 3.1 score 5.9, AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N) because exploitation requires an on-path attacker together with a specific request sequence; this is lower than the CISA score of 7.5, which assumes low attack complexity. The affected Red Hat JBoss Fuse 7 stream (fuse-7-els-2) is not in full support scope, so the flaw has been recorded as out of support scope and no Red Hat update is currently planned for that stream; applications that initiate StartTLS while a search request is still outstanding remain exposed to the residual risk of cleartext disclosure of directory data.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Integrity,Confidentiality
Technical Impact: Read Application Data; Modify Files or Directories
Anyone can read the information by gaining access to the channel being used for communication. Many communication channels can be "sniffed" (monitored) by adversaries during data transmission. For example, in networking, packets can traverse many intermediary nodes from the source to the destination, whether across the internet, an internal network, the cloud, etc. Some actors might have privileged access to a network interface or any link along the channel, such as a router, but they might not be authorized to collect the underlying data. As a result, network traffic could be sniffed by adversaries, spilling security-critical data.
Integrity,Confidentiality
Technical Impact: Read Application Data; Modify Files or Directories; Other
When full communications are recorded or logged, such as with a packet dump, an adversary could attempt to obtain the dump long after the transmission has occurred and try to "sniff" the cleartext from the recorded communications in the dump itself. Even if the information is encoded in a way that is not human-readable, certain techniques could determine which encoding is being used, then decode the information.
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