CVE-2026-11791
CVE-2026-11791 is a medium-severity vulnerability in Redhat Directory Server with a CVSS 3.x base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.
Key facts
- Severity: Medium (CVSS 3.x base score 5.0)
- EPSS exploit prediction: 0% (12th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-37902
- Weakness: CWE-416
- Affected product: Redhat Directory Server
- Published:
- Last modified:
Description
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).
Frequently asked questions
- What is CVE-2026-11791?
- 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).
- How severe is CVE-2026-11791?
- CVE-2026-11791 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.
- Is CVE-2026-11791 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-11791?
- CVE-2026-11791 primarily affects Redhat Directory Server. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-11791?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-11791 have an EU (EUVD) identifier?
- Yes. CVE-2026-11791 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37902.
- When was CVE-2026-11791 published?
- CVE-2026-11791 was published on 2026-06-18 and last updated on 2026-06-30.
References
- https://access.redhat.com/security/cve/CVE-2026-11791
- https://bugzilla.redhat.com/show_bug.cgi?id=2485414
EU advisories (EUVD)
Affected products (8)
- cpe:2.3:a:redhat:directory_server:11.0:*:*:*:*:*:*:*
- cpe:2.3:a:redhat:directory_server:12.0:*:*:*:*:*:*:*
- cpe:2.3:a:redhat:directory_server:13.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:389_directory_server:-:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
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