CVE-2026-18651: redhat 389_directory_server Improper Authentication
Vulnerability summary
CVE-2026-18651 is a medium (CVSS 5.4) Improper Authentication vulnerability in redhat 389_directory_server. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 19.4% of scored vulnerabilities.
Timeline
- 03-08-2026PublishedVulnerability first disclosed.
- 03-08-2026Last modifiedVulnerability information updated.
Description
A flaw was found in 389 Directory Server. During SASL PLAIN authentication, the server installs connection-level bind credentials before performing the account-lock check. If the account is subsequently found to be locked, the bind is reported as failed to the client, but the already-installed authenticated state on the connection is not reverted. A client that supplies valid credentials for an account that has been administratively locked can continue to use the same connection with that account's privileges, defeating account lock as an access-revocation control.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- OSV · DebianEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- NVDNIST5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS trend
Probability
0.28%
Chance of exploitation in the next 30 days
Percentile
19%
Versus all other CVEs
30-day change
+0.11 pp
From 0.17% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Redhat3 products
- 389_directory_serverna
- directory_server11.0 | 12.0 | 13.0
- enterprise_linuxEOL7.0 | 8.0 | 9.0 | 10.0
Debian1 product
- 389-ds-baseAll versions (No fix recorded)
Ubuntu1 product
- 389-ds-baseAll versions (No fix recorded)
3 vendors · 5 products
