CVE-2026-18663

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM 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: 0.5%CVSS: 5.9Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
5.9MEDIUMmedium confidence
EG Risk
27
EG Risk 27/100CISA SSVC

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%
Exploitation1% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
41st
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

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.

Affected Packages

(2 across 2 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
389-ds-base2.3.1+dfsg1-1 ... 3.3.1-3 (18 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
389-ds-base3.1.2+dfsg1-1 ... 3.3.1-3 (8 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 68× 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.

Showing the most recent 100 of 143 total refreshes for this CVE.

  1. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 22:32 UTCGHSA enrichment
  3. 2026-10-03 20:16 UTCEG score recompute
  4. 2026-10-03 20:15 UTCGHSA enrichment
  5. 2026-10-02 08:23 UTCEG score recompute
  6. 2026-10-02 08:23 UTCGHSA enrichment
  7. 2026-10-01 19:49 UTCEPSS rescore
  8. 2026-09-30 21:58 UTCEG score recompute
  9. 2026-09-30 21:58 UTCGHSA enrichment
  10. 2026-09-30 15:02 UTCEPSS rescore
  11. 2026-09-29 15:20 UTCEPSS rescore
  12. 2026-09-29 05:34 UTCEG score recompute
  13. 2026-09-29 05:34 UTCGHSA enrichment
  14. 2026-09-28 13:51 UTCEPSS rescore
  15. 2026-09-28 07:45 UTCEG score recompute
  16. 2026-09-28 07:45 UTCGHSA enrichment
  17. 2026-09-27 13:47 UTCEPSS rescore
  18. 2026-09-27 09:57 UTCEG score recompute
  19. 2026-09-27 09:57 UTCGHSA enrichment
  20. 2026-09-26 15:58 UTCEPSS rescore
  21. 2026-09-25 03:43 UTCEG score recompute
  22. 2026-09-25 03:43 UTCGHSA enrichment
  23. 2026-09-23 20:55 UTCEG score recompute
  24. 2026-09-23 20:55 UTCGHSA enrichment
  25. 2026-09-22 21:07 UTCEG score recompute
Show 75 more
  1. 2026-09-22 21:07 UTCGHSA enrichment
  2. 2026-09-21 20:13 UTCEG score recompute
  3. 2026-09-21 20:13 UTCGHSA enrichment
  4. 2026-09-20 18:56 UTCGHSA enrichment
  5. 2026-09-19 19:59 UTCEG score recompute
  6. 2026-09-19 19:59 UTCGHSA enrichment
  7. 2026-09-18 22:12 UTCEG score recompute
  8. 2026-09-18 22:12 UTCGHSA enrichment
  9. 2026-09-18 19:27 UTCEPSS rescore
  10. 2026-09-17 22:29 UTCEG score recompute
  11. 2026-09-17 22:28 UTCGHSA enrichment
  12. 2026-09-17 00:23 UTCEG score recompute
  13. 2026-09-17 00:23 UTCGHSA enrichment
  14. 2026-09-16 14:07 UTCEPSS rescore
  15. 2026-09-16 05:14 UTCEPSS rescore
  16. 2026-09-15 15:47 UTCEG score recompute
  17. 2026-09-15 15:46 UTCGHSA enrichment
  18. 2026-09-14 17:20 UTCGHSA enrichment
  19. 2026-09-13 19:33 UTCEG score recompute
  20. 2026-09-13 19:33 UTCGHSA enrichment
  21. 2026-09-13 16:46 UTCEPSS rescore
  22. 2026-09-12 21:45 UTCEG score recompute
  23. 2026-09-12 21:45 UTCGHSA enrichment
  24. 2026-09-12 15:00 UTCEPSS rescore
  25. 2026-09-11 23:57 UTCEG score recompute
  26. 2026-09-11 23:57 UTCGHSA enrichment
  27. 2026-09-11 14:52 UTCEPSS rescore
  28. 2026-09-11 09:36 UTCEPSS rescore
  29. 2026-09-11 00:58 UTCEG score recompute
  30. 2026-09-11 00:58 UTCGHSA enrichment
  31. 2026-09-10 09:34 UTCEPSS rescore
  32. 2026-09-10 03:08 UTCGHSA enrichment
  33. 2026-09-09 05:19 UTCEG score recompute
  34. 2026-09-09 05:19 UTCGHSA enrichment
  35. 2026-09-08 22:00 UTCEPSS rescore
  36. 2026-09-07 18:12 UTCEG score recompute
  37. 2026-09-07 18:12 UTCGHSA enrichment
  38. 2026-09-07 16:01 UTCEPSS rescore
  39. 2026-09-06 20:25 UTCEG score recompute
  40. 2026-09-06 20:25 UTCGHSA enrichment
  41. 2026-09-06 13:47 UTCEPSS rescore
  42. 2026-09-05 22:33 UTCEG score recompute
  43. 2026-09-05 22:33 UTCGHSA enrichment
  44. 2026-09-05 00:45 UTCEG score recompute
  45. 2026-09-05 00:45 UTCGHSA enrichment
  46. 2026-09-04 05:06 UTCEPSS rescore
  47. 2026-09-04 01:37 UTCGHSA enrichment
  48. 2026-09-02 23:40 UTCEG score recompute
  49. 2026-09-02 23:40 UTCGHSA enrichment
  50. 2026-09-02 14:11 UTCEPSS rescore
  51. 2026-09-02 00:06 UTCEG score recompute
  52. 2026-09-02 00:05 UTCGHSA enrichment
  53. 2026-09-01 13:53 UTCEPSS rescore
  54. 2026-09-01 04:39 UTCEPSS rescore
  55. 2026-09-01 02:16 UTCGHSA enrichment
  56. 2026-08-31 04:16 UTCEG score recompute
  57. 2026-08-31 04:16 UTCGHSA enrichment
  58. 2026-08-30 19:17 UTCEPSS rescore
  59. 2026-08-30 06:28 UTCEG score recompute
  60. 2026-08-30 06:28 UTCGHSA enrichment
  61. 2026-08-30 01:22 UTCEPSS rescore
  62. 2026-08-29 08:41 UTCEG score recompute
  63. 2026-08-29 08:40 UTCGHSA enrichment
  64. 2026-08-28 21:41 UTCEPSS rescore
  65. 2026-08-28 10:39 UTCEG score recompute
  66. 2026-08-28 10:39 UTCGHSA enrichment
  67. 2026-08-27 14:25 UTCEPSS rescore
  68. 2026-08-27 12:50 UTCGHSA enrichment
  69. 2026-08-26 15:02 UTCEG score recompute
  70. 2026-08-26 15:02 UTCGHSA enrichment
  71. 2026-08-26 14:46 UTCEPSS rescore
  72. 2026-08-25 17:13 UTCEG score recompute
  73. 2026-08-25 17:13 UTCGHSA enrichment
  74. 2026-08-25 13:48 UTCEPSS rescore
  75. 2026-08-24 19:01 UTCEG score recompute

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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 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 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18663?
CVE-2026-18663 has a CVSS base score of 5.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-18663?
A fix for CVE-2026-18663 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-18663 are linked in the Vendor Advisories panel on this page.

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