CVE-2026-18663

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreHIGH confidence

Score 5.9 from GitHub Security Advisory published 2026-08-12. a secondary CVSS source baseline 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
5.9
EG Score
5.9(high)
EG Risk
27(Track)
EG Risk 27/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

August 12, 2026

Last Modified

August 14, 2026

Advisory Details (2)

Auto-updated Aug 12, 2026
Patch available. Sources: redhat.
redhat

2510631 – (CVE-2026-18663) CVE-2026-18663 389-ds-base: 389-ds-base: pre-authentication double-free in get_ldapmessage_controls_ext() via critical Session Tracking control

https://bugzilla.redhat.com/show_bug.cgi?id=2510631
redhat Patch Available

CVE-2026-18663 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-18663

Vendor Advisories for CVE-2026-18663(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 24× in last 7d / 35× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 03:51 UTCEG score recompute
  2. 2026-08-21 03:51 UTCGHSA enrichment
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 06:04 UTCEG score recompute
  5. 2026-08-20 06:04 UTCGHSA enrichment
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-19 08:16 UTCEG score recompute
  8. 2026-08-19 08:16 UTCGHSA enrichment
  9. 2026-08-18 13:48 UTCEPSS rescore
  10. 2026-08-18 10:28 UTCEG score recompute
  11. 2026-08-18 10:28 UTCGHSA enrichment
  12. 2026-08-17 13:47 UTCEPSS rescore
  13. 2026-08-17 12:40 UTCEG score recompute
  14. 2026-08-17 12:40 UTCGHSA enrichment
  15. 2026-08-16 14:56 UTCEPSS rescore
  16. 2026-08-16 14:53 UTCEG score recompute
  17. 2026-08-16 14:53 UTCGHSA enrichment
  18. 2026-08-16 02:14 UTCEPSS rescore
  19. 2026-08-15 17:06 UTCEG score recompute
  20. 2026-08-15 17:06 UTCGHSA enrichment
  21. 2026-08-15 01:30 UTCEPSS rescore
  22. 2026-08-14 19:18 UTCGHSA enrichment
  23. 2026-08-14 14:18 UTCEG score recompute
  24. 2026-08-14 14:18 UTCGHSA enrichment
  25. 2026-08-13 22:00 UTCEPSS rescore
Show 10 more
  1. 2026-08-13 16:30 UTCEG score recompute
  2. 2026-08-13 16:30 UTCGHSA enrichment
  3. 2026-08-13 16:02 UTCEG score recompute
  4. 2026-08-13 16:02 UTCGHSA enrichment
  5. 2026-08-13 08:18 UTCEG score recompute
  6. 2026-08-13 08:18 UTCGHSA enrichment
  7. 2026-08-12 13:50 UTCEPSS rescore
  8. 2026-08-12 10:31 UTCEG score recompute
  9. 2026-08-12 09:39 UTCEG score recompute
  10. 2026-08-12 09:39 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-18663?
CVE-2026-18663 is a medium vulnerability published on August 12, 2026. A flaw was found in 389-ds-base. The getldapmessagecontrolsext() function frees the parsed controls array on the Session Tracking critical-control rejection path without clearing the SLAPIREQCONTROLS pblock slot. Operation teardown then frees the same pointer again, causing a double-free. An…
When was CVE-2026-18663 disclosed?
CVE-2026-18663 was first published in the National Vulnerability Database on August 12, 2026, with the most recent update on August 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18663 actively exploited?
CVE-2026-18663 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 66.9% of all scored CVEs.
What is the CVSS score of CVE-2026-18663?
CVE-2026-18663 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-18663?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18663, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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