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Fencer Vulns
high 7.5

CVE-2026-86344 json

389-ds-base: 389-ds-base: unauthenticated worker-thread-pool exhaustion via completed-operation-then-incomplete-pdu connection requeue

published 2026-10-01 38 d ago modified 2026-11-05 4 d ago also EUVD-2026-91076

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

A flaw was found in 389-ds-base. An unauthenticated remote attacker can send a complete LDAP operation followed by the first bytes of an incomplete LDAPMessage on the same connection, causing the server to hand that connection to a second worker thread before the first worker's result is flushed. The second worker blocks until nsslapd-ioblocktimeout while holding the connection mutex, preventing delivery of the completed operation's result. Repeating this across a small number of connections proportional to the configured worker-thread pool size exhausts the entire pool under default configuration, denying service to all clients (anonymous and authenticated, plaintext and TLS) for as long as the attacker maintains the connections.

Patch / fix

  • 389-ds SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 2.2.11~git12.1e612cde2-150500.3.54.1
  • 389-ds SLES for SAP 15 SP6, SLES 15 SP6-LTSS 2.2.11~git12.1e612cde2-150600.8.38.1

suse advisories SUSE-SU-2026:4932-1SUSE-SU-2026:4929-1

  • 389-ds openSUSE Tumbleweed 3.3.1+28b6d8afc-1.1

opensuse advisories openSUSE-SU-2026:12312-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-86344 updated cvss 7.5

389-ds-base: 389-ds-base: unauthenticated worker-thread-pool exhaustion via completed-operation-then-incomplete-PDU connection requeue

  • Red Hat Directory Server 11 389-ds-base, 389-ds-base 1.4.3.39-28.module+el8dsrv+24826+9ffa737d Red Hat Directory Server 12 389-ds-base, 389-ds-base 2.8.0-7.module+el9dsrv+24844+8988a132 Red Hat Directory Server 13 389-ds-base Red Hat Enterprise Linux 8 389-ds-base, cockpit-389-ds, python3-lib389, 389-ds-base-libs, 389-ds-base-snmp, 389-ds-base-legacy-tools Red Hat Enterprise Linux 9 389-ds-base, python3-lib389, 389-ds-base-libs, 389-ds-base-snmp Red Hat Enterprise Linux 10 389-ds-base
    affected: workaround, no fix available
  • Red Hat Enterprise Linux 6 389-ds-base, 389-ds-base-libs Red Hat Enterprise Linux 7 389-ds-base, 389-ds-base-libs, 389-ds-base-snmp
    under investigation

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
37 d ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat Directory Server 11
  • Red Hat Red Hat Directory Server 12
  • Red Hat Red Hat Directory Server 13
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.