CVE-2026-4729

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-03-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

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

Memory safety bugs present in Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
—
EPSS
25.4%
KEV
Not listed

Published

March 24, 2026

Last Modified

July 15, 2026

Advisory Details (6)

Auto-updated Jul 16, 2026
Patch available. Sources: redhat.
redhat

Affected: Red Hat Enterprise Linux 10",

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4729.json
redhat

2450745 – (CVE-2026-4729) CVE-2026-4729 firefox: Memory safety bugs fixed in Firefox 149 and Thunderbird 149

https://bugzilla.redhat.com/show_bug.cgi?id=2450745
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-4729
generic

Security Vulnerabilities fixed in Thunderbird 149 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-23/
generic

Security Vulnerabilities fixed in Firefox 149 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-20/
generic

Client Challenge

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1944033%2C1997282%2C2009213%2C2011412%2C2021925%2C2022034

Vendor Advisories for CVE-2026-4729(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 37× 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 107 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-4729?
CVE-2026-4729 is a critical vulnerability published on March 24, 2026. Memory safety bugs present in Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149 and Thunderbird 149.
When was CVE-2026-4729 disclosed?
CVE-2026-4729 was first published in the National Vulnerability Database on March 24, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4729 actively exploited?
CVE-2026-4729 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 25.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-4729?
CVE-2026-4729 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-4729?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4729, 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-2026-4729

Explore →

Is Your Infrastructure Affected by CVE-2026-4729?

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

Start Free Scan →Browse All CVEs