389-ds-base: 389-ds-base: unbounded ldap controls count in get_ldapmessage_controls_ext() causes cpu and heap amplification (remote dos)
Summary
| CVE | CVE-2026-9064 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-20 10:16:28 UTC |
| Updated | 2026-07-15 01:17:07 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.008150000 probability, percentile 0.529580000 (date 2026-07-16)
Problem Types: CWE-770 | CWE-770 Allocation of Resources Without Limits or Throttling
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Redhat | 389 Directory Server | - | All | All | All |
| Application | Redhat | Directory Server | 11.0 | All | All | All |
| Application | Redhat | Directory Server | 12.0 | All | All | All |
| Application | Redhat | Directory Server | 13.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 10.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 6.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 7.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 8.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 9.0 | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Directory Server 11.5 E4S For RHEL 8 | unaffected 8060020260609102432.0ca98e7e * rpm | Not specified |
| CNA | Red Hat | Red Hat Directory Server 11.7 E4S For RHEL 8 | unaffected 8080020260610130252.f969626e * rpm | Not specified |
| CNA | Red Hat | Red Hat Directory Server 11.9 For RHEL 8 | unaffected 8100020260601104139.37ed7c03 * rpm | Not specified |
| CNA | Red Hat | Red Hat Directory Server 12.2 E4S For RHEL 9 | unaffected 9020020260615123354.1674d574 * rpm | Not specified |
| CNA | Red Hat | Red Hat Directory Server 12.4 E4S For RHEL 9 | unaffected 9040020260611130021.1674d574 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 10 | unaffected 0:3.2.0-7.el10_2 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | unaffected 0:3.0.6-18.el10_0 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 Extended Lifecycle Support | unaffected 0:1.3.11.1-12.el7_9 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | unaffected 8100020260601102239.25e700aa * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | unaffected 8040020260609102422.96015a92 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | unaffected 8040020260609102422.96015a92 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | unaffected 8060020260609102416.824efc52 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | unaffected 8060020260609102416.824efc52 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | unaffected 8080020260610125847.6dbb3803 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions | unaffected 8080020260610125847.6dbb3803 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | unaffected 0:2.8.0-7.el9_8 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions | unaffected 0:2.2.4-18.el9_2 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9.4 Update Services For SAP Solutions | unaffected 0:2.4.5-25.el9_4 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | unaffected 0:2.6.1-21.el9_6 * rpm | Not specified |
| CNA | Red Hat | Red Hat Directory Server 13.2 | unaffected 1781714123 * rpm | Not specified |
| CNA | Red Hat | Red Hat Directory Server 12 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Directory Server 13 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Directory Server 11.5 E4S For RHEL 8 | unaffected 8060020260609102432.0ca98e7e * rpm | Not specified |
| ADP | Red Hat | Red Hat Directory Server 11.7 E4S For RHEL 8 | unaffected 8080020260610130252.f969626e * rpm | Not specified |
| ADP | Red Hat | Red Hat Directory Server 11.9 For RHEL 8 | unaffected 8100020260601104139.37ed7c03 * rpm | Not specified |
| ADP | Red Hat | Red Hat Directory Server 12.2 E4S For RHEL 9 | unaffected 9020020260615123354.1674d574 * rpm | Not specified |
| ADP | Red Hat | Red Hat Directory Server 12.4 E4S For RHEL 9 | unaffected 9040020260611130021.1674d574 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 10 | unaffected 0:3.2.0-7.el10_2 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | unaffected 0:3.0.6-18.el10_0 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 7 Extended Lifecycle Support | unaffected 0:1.3.11.1-12.el7_9 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8 | unaffected 8100020260601102239.25e700aa * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | unaffected 8040020260609102422.96015a92 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | unaffected 8040020260609102422.96015a92 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | unaffected 8060020260609102416.824efc52 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | unaffected 8060020260609102416.824efc52 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | unaffected 8080020260610125847.6dbb3803 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions | unaffected 8080020260610125847.6dbb3803 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 9 | unaffected 0:2.8.0-7.el9_8 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions | unaffected 0:2.2.4-18.el9_2 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 9.4 Update Services For SAP Solutions | unaffected 0:2.4.5-25.el9_4 * rpm | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | unaffected 0:2.6.1-21.el9_6 * rpm | Not specified |
| ADP | Red Hat | Red Hat Directory Server 13.2 | unaffected 1781714123 * rpm | Not specified |
| ADP | Red Hat | Red Hat Directory Server 12 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Directory Server 13 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:26454 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | Issue Tracking, Vendor Advisory |
| access.redhat.com/errata/RHSA-2026:26460 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26465 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26597 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26459 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26456 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26453 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:27125 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9064.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26457 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26452 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26458 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26463 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26461 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26639 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26464 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26455 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26599 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-9064 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | Mitigation, Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Oleh Konko (1seal.org) for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-03-05T00:00:00.000Z | Reported to Red Hat. |
| CNA | 2026-05-20T07:30:00.000Z | Made public. |
| ADP | 2026-03-05T00:00:00.000Z | Reported to Red Hat. |
| ADP | 2026-05-20T07:30:00.000Z | Made public. |
Solutions
ADP: RHSA-2026:26453: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS)
ADP: RHSA-2026:26458: Red Hat Directory Server 11.9 for RHEL 8
ADP: RHSA-2026:26457: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)
ADP: RHSA-2026:26456: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
ADP: RHSA-2026:26459: Red Hat Enterprise Linux AppStream (v. 8)
ADP: RHSA-2026:26463: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
ADP: RHSA-2026:26460: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)
ADP: RHSA-2026:26454: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8)
ADP: RHSA-2026:26452: Red Hat Enterprise Linux AppStream E4S (v.9.2)
ADP: RHSA-2026:26464: Red Hat Enterprise Linux AppStream E4S (v.9.4)
ADP: RHSA-2026:26465: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6)
ADP: RHSA-2026:26455: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
ADP: RHSA-2026:26461: Red Hat Directory Server 11.5 E4S for RHEL 8
ADP: RHSA-2026:26597: Red Hat Directory Server 11.7 E4S for RHEL 8
ADP: RHSA-2026:26639: Red Hat Directory Server 12.2 E4S for RHEL 9
ADP: RHSA-2026:26599: Red Hat Directory Server 12.4 E4S for RHEL 9
ADP: RHSA-2026:27125: Red Hat Directory Server 13.2
Workarounds
CNA: Restrict network access to the LDAP port (389/tcp, 636/tcp) to trusted networks only using firewall rules or network ACLs. This prevents untrusted remote attackers from reaching the vulnerable code path. Optionally, lower the nsslapd-maxbersize configuration parameter to reduce the maximum BER message size accepted by the server. Note that this caps bytes, not the number of controls, and does not fully eliminate the amplification. Setting it too low may impact legitimate LDAP operations with large payloads.
ADP: Restrict network access to the LDAP port (389/tcp, 636/tcp) to trusted networks only using firewall rules or network ACLs. This prevents untrusted remote attackers from reaching the vulnerable code path. Optionally, lower the nsslapd-maxbersize configuration parameter to reduce the maximum BER message size accepted by the server. Note that this caps bytes, not the number of controls, and does not fully eliminate the amplification. Setting it too low may impact legitimate LDAP operations with large payloads.