Authentication Bypass in 389 Directory Server (CVE-2026-18651)
Summary
Authentication bypass in 389 Directory Server (CVE-2026-18651). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-18651 has been found in 389 Directory Server.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "389 Directory Server CVE-2026-18651" on the vendor's site.
CVE-2026-18651 (389 Directory Server) — CWE-287 / CVSS v3 5.4
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Authentication bypass (CWE-287) exists in 389 Directory Server.
Check the vendor advisory for the affected versions of 389 Directory Server.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで 389 Directory Server を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-18651 389-ds-base
- Ubuntu UBUNTU-CVE-2026-18651 389-ds-base
References
- patch secalert@redhat.com
- patch secalert@redhat.com
- web nvd.nist.gov
- web github.com