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CVE Record

CVE-2026-9064: 389-ds-base: 389-ds-base: unbounded ldap controls count in get_ldapmessage_controls_ext() causes cpu and heap amplification (remote dos)

A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function in the LDAP server does not enforce an upper bound on the number of controls per LDAP message. A remote, unauthenticated attacker can send a specially crafted LDAP request containing hundreds of thousands of minimal controls within the default maximum BER message size (2 MB), causing excessive CPU consumption and heap allocation on the server. Under concurrent exploitation, this leads to significant latency degradation, worker thread starvation, or out-of-memory termination, resulting in a denial of service.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A remote attacker can overwhelm affected 389 Directory Server systems without logging in. Malicious LDAP requests can consume disproportionate CPU and memory, slowing directory services, exhausting worker threads, or crashing the server. This threatens availability, including authentication and other services that depend on the directory, but the supplied evidence does not indicate data theft or modification.

Executive priority

Treat as high priority for internet-facing, broadly reachable, or identity-critical directory servers. An outage could disrupt authentication and dependent business services. Prioritize exposure reduction and vendor updates, while investigating recent unexplained resource exhaustion. Systems isolated to tightly trusted networks have lower immediate likelihood, but remain vulnerable if an internal host is compromised.

Technical view

get_ldapmessage_controls_ext() does not limit the number of LDAP controls in a message. A request within the default 2 MB BER limit can contain hundreds of thousands of minimal controls, amplifying CPU and heap use. Concurrent requests may cause latency, thread starvation, or out-of-memory termination. CVSS 3.1 is 7.5: network-accessible, low complexity, unauthenticated, availability-only impact.

Likely exposure

Exposure exists where an affected 389-ds-base or listed Red Hat Directory Server deployment accepts LDAP connections from untrusted or compromised networks. The supplied affected inventory includes specified builds across Red Hat Directory Server 11 and 12 and RHEL 7 ELS, 8, 9, and 10 channels. Exact package and advisory applicability must be verified per system.

Exploitation context

The flaw is remotely reachable, requires no authentication or user interaction, and has low attack complexity. Concurrent abuse increases denial-of-service impact. The supplied data marks the CVE as absent from KEV and provides no cited evidence of active exploitation; this does not prove exploitation has never occurred.

Researcher notes

This is CWE-770 resource allocation without limits. The key amplification boundary is control count rather than total message size: many minimal controls fit inside the default 2 MB BER limit. Impact is confined by the supplied CVSS assessment to availability. The bundle does not provide a safe control-count threshold, detection signature, or complete cross-vendor version boundary.

Mitigation direction

  • Identify affected 389-ds-base and Red Hat Directory Server installations, including their exact package builds and support channels.
  • Review the applicable Red Hat CVE page and RHSA advisory for vendor-approved remediation.
  • Apply the vendor-provided update appropriate to each product and support channel after normal validation.
  • Until updated, restrict LDAP reachability to trusted networks and clients where operationally feasible.
  • Monitor directory servers for abnormal CPU, memory, latency, worker exhaustion, and unexpected restarts.

Validation and detection

  • Inventory installed 389-ds-base or redhat-ds packages and compare exact builds with applicable Red Hat advisories.
  • Confirm whether LDAP listeners are reachable from internet, partner, user, container, or other untrusted network segments.
  • Verify updated package versions against the advisory matching each RHEL or Directory Server support channel.
  • Review monitoring and system logs for resource spikes, thread starvation, out-of-memory events, and unexplained directory-service interruptions.
  • Perform controlled availability and dependency checks after remediation without reproducing malicious traffic.
Prepared
Confidence
high
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-770: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-9064 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
7Timeline events
2ADP providers
21Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-9064Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. ADP timelineredhat-SADP

    Reported to Red Hat.

  2. Source timelineredhat

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. Source timelineredhat

    Made public.

  5. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  6. CVE publishedCVE Program

    The CVE record was published.

  7. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADP389-ds-base: 389-ds-base: unbounded LDAP controls count in get_ldapmessage_controls_ext() causes CPU and heap amplification (remote DoS)
other:Red Hat severity ratingcvssV3_1
  • 2026-03-05T00:00:00.000Z: Reported to Red Hat.
  • 2026-05-20T07:30:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Unknown vendor389-ds-base389-ds-base, 0Listed
Red HatRed Hat Directory Server 11.5 E4S for RHEL 8redhat-ds:11, 8060020260609102432.0ca98e7eaffected
Red HatRed Hat Directory Server 11.7 E4S for RHEL 8redhat-ds:11, 8080020260610130252.f969626eaffected
Red HatRed Hat Directory Server 11.9 for RHEL 8redhat-ds:11, 8100020260601104139.37ed7c03affected
Red HatRed Hat Directory Server 12.2 E4S for RHEL 9redhat-ds:12, 9020020260615123354.1674d574affected
Red HatRed Hat Directory Server 12.4 E4S for RHEL 9redhat-ds:12, 9040020260611130021.1674d574affected
Red HatRed Hat Enterprise Linux 10389-ds-base, 0:3.2.0-7.el10_2affected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support389-ds-base, 0:3.0.6-18.el10_0affected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Support389-ds-base, 0:1.3.11.1-12.el7_9affected
Red HatRed Hat Enterprise Linux 8389-ds:1.4, 8100020260601102239.25e700aaaffected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support389-ds:1.4, 8040020260609102422.96015a92affected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On389-ds:1.4, 8040020260609102422.96015a92affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support389-ds:1.4, 8060020260609102416.824efc52affected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On389-ds:1.4, 8060020260609102416.824efc52affected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Service389-ds:1.4, 8080020260610125847.6dbb3803affected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutions389-ds:1.4, 8080020260610125847.6dbb3803affected
Red HatRed Hat Enterprise Linux 9389-ds-base, 0:2.8.0-7.el9_8affected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutions389-ds-base, 0:2.2.4-18.el9_2affected
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutions389-ds-base, 0:2.4.5-25.el9_4affected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Support389-ds-base, 0:2.6.1-21.el9_6affected
Red HatRed Hat Directory Server 13.2dirsrv/dirsrv-container-rhel10, 1781714123affected
Red HatRed Hat Directory Server 12redhat-ds:12/389-ds-baseaffected
Red HatRed Hat Directory Server 13389-ds-baseaffected
Red HatRed Hat Enterprise Linux 6389-ds-baseunknown
Weakness

CWE details

CWE-770

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-770 · source CWE mapping

Allocation of Resources Without Limits or Throttling

Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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