CVE-2026-18663: 389-ds-base · CWE-415
Source GCVE Database
Not known to be exploited · CVSS 5.9 Medium : upgrade the Red Hat redhat/389-ds-base package to 4.0.0 when convenient.
Data as of 10 Nov 2026, 23:24 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 5.9 |
|---|
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.0.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade the Red Hat redhat/389-ds-base package to 4.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Red Hatredhat/389-ds-basepkg:rpm/redhat/389-ds-baseOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat advises administrators on affected builds to add the Session Tracking control OID (1.3.6.1.4.1.21008.108.63.1) to the ds-ignored-control-criticality configuration attribute to prevent the vulnerable rejection path. Additionally, restricting network access to LDAP ports (389/636) to trusted clients reduces exposure. Red Hat product builds using jemalloc are not reliably affected.
Description
A double-free vulnerability exists in 389-ds-base 3.x in the get_ldapmessage_controls_ext() function when processing a critical Session Tracking control during an unauthenticated BIND request. This causes heap corruption and can lead to denial of service on builds using the glibc allocator. Red Hat product builds using jemalloc are not reliably affected. No information disclosure or privilege escalation has been demonstrated.