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CVE-2026-11884 Red Hat CVE debrief

CVE-2026-11884 is a heap buffer overflow vulnerability in 389 Directory Server. The vulnerability occurs when serializing objectclass definitions, where the oc_superior (SUP) field length is omitted from buffer size calculations in read_schema_dse() and schema_oc_to_string(), but the field is still written via strcat(). An attacker with Directory Manager privileges, or a compromised replication supplier, can trigger a server crash by creating objectclasses with long SUP values. This is an incomplete fix variant of CVE-2025-14905.

Vendor
Red Hat
Product
Red Hat Directory Server 11
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-10
Original CVE updated
2026-06-30
Advisory published
2026-06-10
Advisory updated
2026-06-30

Who should care

Users of 389 Directory Server should be aware of this vulnerability and take steps to mitigate it.

Technical summary

Heap buffer overflow vulnerability in 389 Directory Server when serializing objectclass definitions.

Defensive priority

MEDIUM

Recommended defensive actions

  • Apply the patches or updates provided by the vendor to fix the vulnerability.
  • Restrict access to Directory Manager privileges to trusted users.
  • Monitor replication suppliers for potential compromise.

Evidence notes

The CVE-2026-11884 vulnerability was reported by Red Hat.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-11884 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-11884

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-11884 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-11884

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.