5.9

CVE-2026-18663: 389-ds-base Double Free

CVSS: 5.9v3.1MediumAwaiting analysis
AliasesUBUNTU-CVE-2026-18663DEBIAN-CVE-2026-18663
Published 12-08-2026Last modified 13-08-2026
Open JSON

Vulnerability summary

CVE-2026-18663 is a medium (CVSS 5.9) Double Free vulnerability in 389-ds-base. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 42.7% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
5.9/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.51%
0%100%
Low · +0.08 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:11739-1

Timeline

  1. 12-08-2026
    PublishedVulnerability first disclosed.
  2. 13-08-2026
    Last modifiedVulnerability information updated.

Description

A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function frees the parsed controls array on the Session Tracking critical-control rejection path without clearing the SLAPI_REQCONTROLS pblock slot. Operation teardown then frees the same pointer again, causing a double-free. An unauthenticated remote attacker can trigger this with a single BIND request carrying a critical Session Tracking control, resulting in heap corruption and potential denial of service.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.51%

Chance of exploitation in the next 30 days

Percentile

43%

Versus all other CVEs

30-day change

+0.08 pp

From 0.43% on 22-09-2026

22-09-202622-10-2026
EPSS score
0.51%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • 389-ds-baseAll versions (No fix recorded)
Ubuntu1 product
  • 389-ds-baseAll versions (No fix recorded)

2 vendors · 2 products

References

5 links