CVE-2026-6747

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-04-21. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

Use-after-free in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
34%
KEV
Not listed

Published

April 21, 2026

Last Modified

July 15, 2026

Advisory Details (5)

Auto-updated Jun 9, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 140.10 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-34/
generic

Security Vulnerabilities fixed in Thunderbird 150 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-33/
generic

Security Vulnerabilities fixed in Firefox ESR 140.10 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-32/
generic

Security Vulnerabilities fixed in Firefox 150 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-30/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2021769

Vendor Advisories for CVE-2026-6747(20)

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

Patch Availability(27)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatthunderbird-0:140.10.0-1.el8_42026-05-20redhat
redhatfirefox-0:140.10.0-1.el9_42026-05-20redhat
redhatthunderbird-0:140.10.0-1.el8_62026-05-20redhat
redhatfirefox-0:140.10.0-1.el8_62026-05-20redhat
redhatthunderbird-0:140.10.0-1.el9_02026-05-20redhat
redhatthunderbird-0:140.10.0-1.el10_02026-05-20redhat
redhatthunderbird-0:140.10.0-1.el9_42026-05-20redhat
redhatthunderbird-0:140.10.0-1.el9_62026-05-20redhat
redhatfirefox-0:140.10.0-1.el8_42026-05-20redhat
redhatthunderbird-0:140.10.0-1.el9_22026-05-20redhat
redhatthunderbird-0:140.10.0-1.el8_82026-05-20redhat
redhatfirefox-0:140.10.0-2.el7_92026-05-20redhat
redhatthunderbird-0:140.10.1-1.el9_82026-05-19redhat
redhatfirefox-0:140.10.0-1.el9_82026-05-19redhat
redhatfirefox-0:140.10.0-1.el10_22026-05-19redhat
redhatthunderbird-0:140.10.0-1.el10_22026-05-19redhat
redhatfirefox-0:140.10.0-1.el9_22026-05-14redhat
redhatfirefox-0:140.10.0-1.el9_62026-05-14redhat
redhatfirefox-0:140.10.0-1.el8_82026-05-14redhat
redhatfirefox-0:140.10.0-1.el9_02026-05-14redhat
redhatfirefox-0:140.10.0-1.el10_02026-05-14redhat
redhatthunderbird-0:140.10.0-1.el9_72026-05-11redhat
redhatthunderbird-0:140.10.0-1.el8_102026-05-04redhat
redhatthunderbird-0:140.10.0-1.el10_12026-04-30redhat
redhatfirefox-0:140.10.0-1.el10_12026-04-27redhat
redhatfirefox-0:140.10.0-1.el9_72026-04-27redhat
redhatfirefox-0:140.10.0-1.el8_102026-04-27redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(8 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.1.0esr-1 ... 91.9.1esr-1~deb9u1 (263 versions)140.10.0esr-1~deb11u1—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (314 versions)1:140.10.0esr-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.9.1esr-1~deb13u1 (170 versions)140.10.0esr-1~deb12u1—
thunderbird1:102.11.0-1 ... 1:140.9.1esr-1~deb13u1 (199 versions)1:140.10.0esr-1~deb12u1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (46 versions)140.10.0esr-1~deb13u1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (55 versions)1:140.10.0esr-1~deb13u1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (47 versions)140.10.0esr-1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (56 versions)1:140.10.0esr-1—

Weakness Classification(2)

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

Additional Vendor Advisories

(7)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 5× in last 7d / 26× 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 218 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-6747?
CVE-2026-6747 is a high vulnerability published on April 21, 2026. Use-after-free in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
When was CVE-2026-6747 disclosed?
CVE-2026-6747 was first published in the National Vulnerability Database on April 21, 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-2026-6747 actively exploited?
CVE-2026-6747 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 66.4% of all scored CVEs.
What is the CVSS score of CVE-2026-6747?
CVE-2026-6747 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-6747?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6747, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-6747

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