CVE-2026-4717

CRITICALNVD 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
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

Privilege escalation in the Netmonitor component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS v3
9.8
EG Score
9.8(medium)
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%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

March 24, 2026

Last Modified

June 17, 2026

Advisory Details (5)

Auto-updated Aug 31, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 140.9 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-24/
generic

Security Vulnerabilities fixed in Thunderbird 149 — Mozilla

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

Security Vulnerabilities fixed in Firefox ESR 140.9 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-22/
generic

Security Vulnerabilities fixed in Firefox 149 — Mozilla

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

2021695 - (CVE-2026-4717) JavaScript injection via DevTools "Copy as Fetch" / "Use as Fetch in Console" with data: URIs

https://bugzilla.mozilla.org/show_bug.cgi?id=2021695

Vendor Advisories for CVE-2026-4717(20)

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

Patch Availability(25)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatthunderbird-0:140.9.0-1.el8_42026-04-20redhat
redhatfirefox-0:140.9.0-1.el7_92026-04-16redhat
redhatthunderbird-0:140.9.0-1.el9_42026-04-15redhat
redhatthunderbird-0:140.9.0-1.el10_02026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_62026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_02026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_22026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_62026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_82026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_22026-04-15redhat
redhatfirefox-0:140.9.0-1.el8_62026-04-13redhat
redhatfirefox-0:140.9.0-1.el10_02026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_42026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_42026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_62026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_82026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_22026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_02026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_22026-04-13redhat
redhatthunderbird-0:140.9.0-1.el8_102026-04-07redhat
redhatthunderbird-0:140.9.0-1.el10_12026-04-01redhat
redhatthunderbird-0:140.9.0-1.el9_72026-03-30redhat
redhatfirefox-0:140.9.0-1.el9_72026-03-26redhat
redhatfirefox-0:140.9.0-1.el10_12026-03-26redhat
redhatfirefox-0:140.9.0-1.el8_102026-03-26redhat

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 (255 versions)140.9.0esr-1~deb11u1—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (306 versions)1:140.9.0esr-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.8.0esr-1~deb13u1 (161 versions)140.9.0esr-1~deb12u1—
thunderbird1:102.11.0-1 ... 1:140.9.0esr-1~deb11u1 (191 versions)1:140.9.0esr-1~deb12u1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.8.0esr-1~deb13u1 (36 versions)140.9.0esr-1~deb13u1—
thunderbird1:128.13.0esr-1 ... 1:140.9.0esr-1~deb11u1 (46 versions)1:140.9.0esr-1~deb13u1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.0esr-1~deb13u1 (39 versions)140.9.0esr-1—
thunderbird1:128.13.0esr-1 ... 1:140.9.0esr-1~deb13u1 (48 versions)1:140.9.0esr-1—

Additional Vendor Advisories

(5)

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 6× in last 7d / 86× 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 239 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-4717?
CVE-2026-4717 is a critical vulnerability published on March 24, 2026. Privilege escalation in the Netmonitor component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
When was CVE-2026-4717 disclosed?
CVE-2026-4717 was first published in the National Vulnerability Database on March 24, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4717 actively exploited?
CVE-2026-4717 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 65.1% of all scored CVEs.
What is the CVSS score of CVE-2026-4717?
CVE-2026-4717 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-4717?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4717, 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-2026-4717

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