CVE-2026-86345: A flaw was found in 389-ds-base
CVE-2026-86345 analysis covering impact, affected products, versions, remediation, and cross-checked defender guidance.
CVE-2026-86345 is a vulnerability published by NVD on 10/2/2026.
What happened
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.
Affected products and versions
- NVD has not published a normalized affected-product configuration yet.
Severity and weakness
CVSS: CRITICAL 9. Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.
Weaknesses: CWE-923.
Known exploitation
No CISA KEV entry is currently attached to the NVD record.
What defenders should do
- Identify whether the affected product and version range exists in production.
- Review vendor advisories and release notes before change windows.
- Patch, upgrade, disable the vulnerable component, or apply vendor mitigations.
- Verify the running version after deployment, not only the package inventory.
Official and supporting references
- No vendor advisory tagged by NVD at draft time.