- Critical 9.0
CVE-2026-86345
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.
Scores
The facts
- Published
- 2 October 2026
- Last changed
- 7 October 2026
- NVD status
- Awaiting Analysis
- Severity
- Critical, CVSS 9.0 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- Known exploited
- Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
- EPSS
- 0.4% chance of exploitation activity in the next 30 days (percentile 31).
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