AI Threat Alert
CVE-2026-18663
MEDIUMA 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...
Full CISO analysis pending enrichment.
What systems are affected?
| Package | Ecosystem | Vulnerable Range | Patched |
|---|---|---|---|
| 389-ds-base | — | — | No patch |
| 389-ds:1.4/389-ds-base | — | — | No patch |
| redhat-ds:11/389-ds-base | — | — | No patch |
| redhat-ds:12/389-ds-base | — | — | No patch |
How severe is it?
What is the attack surface?
What should I do?
No patch available
Monitor for updates. Consider compensating controls or temporary mitigations.
Which compliance frameworks are affected?
Compliance analysis pending. Sign in for full compliance mapping when available.
Frequently Asked Questions
What is CVE-2026-18663?
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.
Is CVE-2026-18663 actively exploited?
No confirmed active exploitation of CVE-2026-18663 has been reported, but organizations should still patch proactively.
How to fix CVE-2026-18663?
No patch is currently available. Monitor vendor advisories for updates.
What is the CVSS score for CVE-2026-18663?
CVE-2026-18663 has a CVSS v3.1 base score of 5.9 (MEDIUM).
What are the technical details?
Original Advisory
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.
Weaknesses (CWE)
CWE-415 — Double Free: The product calls free() twice on the same memory address.
- [Architecture and Design] Choose a language that provides automatic memory management.
- [Implementation] Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
Source: MITRE CWE corpus.
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H References
- access.redhat.com/security/cve/CVE-2026-18663 vdb-entry x_refsource_REDHAT
- bugzilla.redhat.com/show_bug.cgi issue-tracking x_refsource_REDHAT