CVE-2026-86345
Critical
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.
SeverityCritical
CVSS9.0
Exploit probability—
Product
Red Hat Directory Server 11
PublishedOct 2, 2026
First seenOct 2, 2026
Weakness typeCWE-923CWE-923
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Red Hat Directory Server 11 | No range specified | — |
| Red Hat Red Hat Directory Server 12 | No range specified | — |
| Red Hat Red Hat Directory Server 13 | No range specified | — |
| Red Hat Red Hat Enterprise Linux 10 | No range specified | — |
| Red Hat Red Hat Enterprise Linux 8 | No range specified | — |
| Red Hat Red Hat Enterprise Linux 9 | No range specified | — |
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