CVE-2026-6757

MEDIUMPre-NVD 6.36.3—
EchelonGraph scoreMEDIUM confidence

Score 6.3 from GitHub Security Advisory published 2026-04-21. the CNA's CVSS baseline 6.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:mozilla, epss, ghsa
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.3Exploit: None knownExposed: 0

A fix is available — apply it.

Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS v3
6.3
EG Score
6.3(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity63% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

April 21, 2026

Last Modified

May 26, 2026

Advisory Details (5)

Auto-updated Aug 2, 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=2013588

Vendor Advisories for CVE-2026-6757(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
redhatfirefox-0:140.10.0-2.el7_92026-05-20redhat
redhatthunderbird-0:140.10.0-1.el8_82026-05-20redhat
redhatfirefox-0:140.10.0-1.el8_42026-05-20redhat
redhatthunderbird-0:140.10.0-1.el9_42026-05-20redhat
redhatthunderbird-0:140.10.0-1.el8_62026-05-20redhat
redhatthunderbird-0:140.10.0-1.el10_02026-05-20redhat
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.el9_22026-05-20redhat
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.el9_62026-05-20redhat
redhatthunderbird-0:140.10.1-1.el9_82026-05-19redhat
redhatfirefox-0:140.10.0-1.el9_82026-05-19redhat
redhatthunderbird-0:140.10.0-1.el10_22026-05-19redhat
redhatfirefox-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.el10_02026-05-14redhat
redhatfirefox-0:140.10.0-1.el9_02026-05-14redhat
redhatfirefox-0:140.10.0-1.el9_62026-05-14redhat
redhatfirefox-0:140.10.0-1.el8_82026-05-14redhat
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.el8_102026-04-27redhat
redhatfirefox-0:140.10.0-1.el10_12026-04-27redhat
redhatfirefox-0:140.10.0-1.el9_72026-04-27redhat

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(1)

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 4× in last 7d / 25× 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 191 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-6757?
CVE-2026-6757 is a medium vulnerability published on April 21, 2026. Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
When was CVE-2026-6757 disclosed?
CVE-2026-6757 was first published in the National Vulnerability Database on April 21, 2026, with the most recent update on May 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-6757 actively exploited?
CVE-2026-6757 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 78.2% of all scored CVEs.
What is the CVSS score of CVE-2026-6757?
CVE-2026-6757 has a CVSS v4.0 base score of 6.3 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-6757?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6757, 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-2026-6757

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