Use-After-Free in 389 Directory Server (CVE-2026-11791)
Summary
Vulnerability in 389 Directory Server (CVE-2026-11791). 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 schema reload, the attr_syntax_swap_ht() function unconditionally frees attribute syntax information nodes, bypassing the refcount-based deferred deletion used elsewhere in the attribute syntax subsystem. If an administrator triggers schema reload while concurrent LDAP query traffic is active, worker threads may access freed memory, resulting in use-after-free or double-free and a denial of service (server crash).
Source: NIST National Vulnerability Database 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-2026-11791 has been found in 389 Directory Server.
Risk of unauthorized operations or information disclosure. CVSS score: 5.0/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "389 Directory Server CVE-2026-11791" on the vendor's site.
CVE-2026-11791 (389 Directory Server) — CWE-416 / CVSS v3 5.0
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.
Use-after-free (CWE-416) exists in 389 Directory Server.
Check the vendor advisory for the affected versions of 389 Directory Server.
Severity: Medium (CVSS 5.0/10). 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-2026-11791 389-ds-base
- Ubuntu UBUNTU-CVE-2026-11791 389-ds-base
References
- patch secalert@redhat.com
- patch secalert@redhat.com
- web secalert@redhat.com
- web nvd.nist.gov
- web github.com