CVE-2026-9966

HIGHPre-NVD 8.38.3—
EchelonGraph scoreMEDIUM confidence

Score 8.3 from GitHub Security Advisory (severity: HIGH) published 2026-05-29. the CNA's CVSS baseline 8.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:chrome, epss, ghsa
Trending — 4 sources updated this week
8.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.3Exploit: NoneExposed: 0

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

Integer overflow in XML in Google Chrome on Windows prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)

CVSS v3
8.3
EG Score
8.3(medium)
EPSS
11.7%
KEV
Not listed

Published

May 28, 2026

Last Modified

May 30, 2026

Advisory Details (2)

Auto-updated Jun 3, 2026
No patch confirmed yet.
generic

Chromium

https://issues.chromium.org/issues/506388321
generic

Chrome Releases: Stable Channel Update for Desktop

https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304591.html

Vendor Advisories for CVE-2026-9966(2)

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 16× in last 7d / 93× 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 208 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-9966?
CVE-2026-9966 is a high vulnerability published on May 28, 2026. Integer overflow in XML in Google Chrome on Windows prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)
When was CVE-2026-9966 disclosed?
CVE-2026-9966 was first published in the National Vulnerability Database on May 28, 2026, with the most recent update on May 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9966 actively exploited?
CVE-2026-9966 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 11.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-9966?
CVE-2026-9966 has a CVSS v4.0 base score of 8.3 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-9966?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9966, 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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