CVE-2026-66909

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-06. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

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

Apache CXF's JMS transport deserializes the body of any inbound JMS ObjectMessage using native Java deserialization, with no type restrictions in place. Any attacker able to place a message on the service's JMS destination can submit a malicious serialized object, leading to denial of service or, if a suitable gadget class is on the classpath, remote code execution. The fix disables ObjectMessage deserialization by default, with a configuration switch to re-enable it if needed. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
50%
KEV
Not listed

Published

August 6, 2026

Last Modified

August 7, 2026

Advisory Details (2)

Auto-updated Aug 14, 2026
No patch confirmed yet.
generic

oss-security - CVE-2026-66909: Apache CXF: Unsafe deserialization of inbound JMS ObjectMessage

http://www.openwall.com/lists/oss-security/2026/08/06/18
generic
https://lists.apache.org/thread/lr5d4tg6tf7j29jmw8wt242oowonjqpx

Vendor Advisories for CVE-2026-66909(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 51× in last 7d / 116× 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 116 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-66909?
CVE-2026-66909 is a critical vulnerability published on August 6, 2026. Apache CXF's JMS transport deserializes the body of any inbound JMS ObjectMessage using native Java deserialization, with no type restrictions in place. Any attacker able to place a message on the service's JMS destination can submit a malicious serialized object, leading to denial of service or,…
When was CVE-2026-66909 disclosed?
CVE-2026-66909 was first published in the National Vulnerability Database on August 6, 2026, with the most recent update on August 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66909 actively exploited?
CVE-2026-66909 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 49.9% of all scored CVEs.
What is the CVSS score of CVE-2026-66909?
CVE-2026-66909 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-66909?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66909, 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

Explore the affected products and dependency analysis for CVE-2026-66909

Explore →

Is Your Infrastructure Affected by CVE-2026-66909?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs