CVE-2026-86345CWE-923

CVE-2026-86345

Critical · published October 2, 2026

CVSS v3.1
9.0
EPSS
0%
Percentile
31.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00382 · 31.0th percentile
Weakness
CWE-923 · Improper Restriction of Communication Channel to Intended Endpoints
Published
2026-10-02T04:17Z
References (2)
https://access.redhat.com/security/cve/CVE-2026-86345 · [email protected]https://bugzilla.redhat.com/show_bug.cgi?id=2529332 · [email protected]
EPSS history
Timeline
  • 08 OCT 03:33Z
    EPSS moved — → 0%
    epss
  • 01 OCT 23:27Z
    389-ds-base: 389-ds-base: starttls plaintext-buffer retention allows on-path attacker to forge an ldap client's authentication result
    cvelistv5
  • 01 OCT 23:27Z
    389-ds-base: 389-ds-base: starttls plaintext-buffer retention allows on-path attacker to forge an ldap client's authentication result
    cvelistv5