CVE-2026-12249

CRITICALPre-NVD 9.09.0—
EchelonGraph scoreMEDIUM confidence

Score 9.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-22. a secondary CVSS source baseline 9.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
9.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.0Exploit: None knownExposed: 0

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

An issue was discovered in Canonical ADSys upstream versions through v0.16.2. During Active Directory Certificate Services (AD CS) certificate auto-enrollment via the vendored Samba client script (internal/policies/certificate/python/vendor_samba/gp/gp_cert_auto_enroll_ext.py), ADSys utilizes a plaintext HTTP connection (http://) instead of a secure HTTPS connection (https://) to request the CA certificate from the Active Directory Certificate Services server (GetCACert). An unauthenticated network attacker positioned between the managed Ubuntu host and the configured AD CS CA hostname can conduct a Man-in-the-Middle (MITM) attack. By intercepting the plaintext HTTP request, the attacker can supply an arbitrary, attacker-controlled Root CA certificate. Because the system automatically accepts this certificate and registers it into the local system trust store via update-ca-certificates, this results in system-wide trust store poisoning. Consequently, TLS clients utilizing the operating system trust store on the affected machine will accept rogue certificates for arbitrary domains, enabling persistent decryption and interception of subsequent TLS connections. This issue is resolved in version v0.16.3.

CVSS v3
9.0
EG Score
9.0(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity90% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

June 22, 2026

Last Modified

June 22, 2026

Advisory Details (1)

Auto-updated Jun 22, 2026
Patch available. Sources: github_commit.
github_commit Patch Available

commit 8b1939f96d38 (ubuntu/adsys)

Patch available: ubuntu/adsys v0.16.3 (contains commit 8b1939f96d38)

https://github.com/ubuntu/adsys/commit/8b1939f96d3827b4426eb06c1ced5bf317b0a99d

Vendor Advisories for CVE-2026-12249(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 38× in last 7d / 194× 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 376 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-12249?
CVE-2026-12249 is a critical vulnerability published on June 22, 2026. An issue was discovered in Canonical ADSys upstream versions through v0.16.2. During Active Directory Certificate Services (AD CS) certificate auto-enrollment via the vendored Samba client script (internal/policies/certificate/python/vendorsamba/gp/gpcertautoenroll_ext.py), ADSys utilizes a…
When was CVE-2026-12249 disclosed?
CVE-2026-12249 was first published in the National Vulnerability Database on June 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12249 actively exploited?
CVE-2026-12249 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 96.2% of all scored CVEs.
What is the CVSS score of CVE-2026-12249?
CVE-2026-12249 has a CVSS v3 base score of 9.0 (NVD).
How do I remediate CVE-2026-12249?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12249, 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.

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