EUVD Vulnerability Catalog

EUVD-2026-91139

Severity: CRITICAL Base Score: 9 CVSS Version: 3.1

Vulnerability Description

A flaw was found in 389-ds-base. The server does not discard plaintext bytes already buffered from a client connection when negotiating StartTLS, allowing an on-path attacker to inject a crafted LDAP message that is processed after the TLS upgrade and whose response is delivered to the client in place of the client's own pending operation's response, due to messageID collision. This can cause a client application to treat a failed authentication (bind) attempt as successful.

CVSS Vector Analysis

Below is the complete, human-readable breakdown of the CVSS metric string: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

▪ Attack Vector (AV): Network

▪ Attack Complexity (AC): High

▪ Privileges Required (PR): None

▪ User Interaction (UI): None

▪ Scope (S): Changed

▪ Confidentiality Impact (C): High

▪ Integrity Impact (I): High

▪ Availability Impact (A): High

References & Advisory Links

Metadata Profile

Database Authority

European Union Agency for Cybersecurity (ENISA) EUVD

Assigner

redhat

EPSS Probability

Known Aliases

GHSA-c4v7-fhgq-r988 CVE-2026-86345

Published On

2026-10-01

Last Updated

2026-10-02