Medium [CVE-2026-11791] 389-ds-base: 389-ds-base: use-after-free in schema reload via attr_syntax_swap_ht
This medium-severity Red Hat Linux advisory covers CVE-2026-11791 affecting Red Hat Directory Server 11, Red Hat Directory Server 12, Red Hat Directory Server 13.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published
Summary
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). Red Hat rates this issue as Moderate impact.
Red Hat assigns AC:H and PR:H because the race window is nanoseconds-wide and stress testing did not produce a natural crash; schema reload requires administrative privileges. Schedule schema reloads during maintenance windows with reduced LDAP traffic.
Red Hat severity: Moderate — CVSS 5 (CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:H). Weakness: CWE-416.
Affected Red Hat products: Red Hat Directory Server 11; Red Hat Directory Server 12; Red Hat Directory Server 13; Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9. Red Hat lists Red Hat Enterprise Linux 6 as not affected.
Red Hat does not currently list a fixing RHSA for this CVE.
Affected products named by the advisory: Red Hat package: 389-ds-base.
Is CVE-2026-11791 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-11791 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-11791?
The advisory VulniPulse tracks names no fixed release. Follow Red Hat's guidance for workarounds and updates.
Confirm against the vendor advisory before you patch.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.
Official advisory · high-confidence parse· fetched 4 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists. Confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 4 days ago·verify at source
Mitigation checklist
- Schedule schema reload operations during maintenance windows with reduced LDAP traffic. Minimize schema reload frequency; in replication topologies schema changes propagate automatically. Monitor for unexpected ns-slapd restarts during or immediately after schema reloads. Restrict write access to cn=schema,cn=config to dedicated administrative accounts via LDAP ACIs.
Official advisory · high-confidence parse· fetched 4 days ago·verify at source
Get an email when Red Hat RHEL & SELinux publishes the next one.
See Red Hat RHEL & SELinux's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).
More Red Hat Linux advisories
- CVE-2026-111497Oct 22, 2026Out-of-Bounds Write in Google Brotli Decoder
- CVE-2026-109619Oct 21, 2026fatal error handling retains stale request state leading to use-after-free
- CVE-2026-109618Oct 21, 2026OOM bailout during request parsing leads to memory corruption and RCE
- CVE-2026-119977Oct 31, 2026Arbitrary code execution via predictable upgrade staging paths
- CVE-2026-97229Oct 13, 2026integer overflow issue in CI/CD regular expression compiler
- CVE-2026-64849Aug 17, 2026Unauthenticated full-read SSRF in webhook delivery: _validate_webhook_url bypassed
iPhone and Android apps · New on the App Store
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.