CVE-2026-4711

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

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, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-14837 (ENISA EUVD) · GHSA-9979-85jw-xp9m (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
37th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

March 24, 2026

Last Modified

June 17, 2026

Advisory Details (5)

Auto-updated Oct 31, 2026
Patch available.
Web page

Security Vulnerabilities fixed in Thunderbird 140.9 — Mozilla

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

Security Vulnerabilities fixed in Thunderbird 149 — Mozilla

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

Security Vulnerabilities fixed in Firefox ESR 140.9 — Mozilla

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

Security Vulnerabilities fixed in Firefox 149 — Mozilla

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

2017002 - (CVE-2026-4711) Use-after-free in macOS sharing service

https://bugzilla.mozilla.org/show_bug.cgi?id=2017002

Patch Availability(25)

Vendor / EcosystemFix (by version range) / 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_02026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_22026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_82026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_62026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_22026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_42026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_62026-04-15redhat
redhatthunderbird-0:140.9.0-1.el10_02026-04-15redhat
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.el8_22026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_22026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_62026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_42026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_02026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_82026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_62026-04-13redhat
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.el8_102026-03-26redhat
redhatfirefox-0:140.9.0-1.el10_12026-03-26redhat
redhatfirefox-0:140.9.0-1.el9_72026-03-26redhat

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.

Weakness Classification(1)

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

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 19× in last 7d / 86× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 394 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 294 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 16:42 UTCEchelonGraph re-scored
  2. 2026-11-12 16:42 UTCVendor advisory
  3. 2026-11-12 16:41 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  5. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  6. 2026-11-11 16:01 UTCEchelonGraph re-scored
  7. 2026-11-11 16:01 UTCVendor advisory
  8. 2026-11-11 16:01 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-11-10 15:21 UTCEchelonGraph re-scored
  11. 2026-11-10 15:21 UTCVendor advisory
  12. 2026-11-10 15:21 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  14. 2026-11-09 14:41 UTCEchelonGraph re-scored
  15. 2026-11-09 14:41 UTCVendor advisory
  16. 2026-11-09 14:41 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  18. 2026-11-08 14:02 UTCEchelonGraph re-scored
  19. 2026-11-08 14:02 UTCVendor advisory
  20. 2026-11-08 14:02 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  22. 2026-11-07 13:21 UTCEchelonGraph re-scored
  23. 2026-11-07 13:21 UTCVendor advisory
  24. 2026-11-07 13:21 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-06 16:38 UTCEPSS rescoreEPSS 0.4% · 35th percentile
Show 75 more
  1. 2026-11-06 12:41 UTCEchelonGraph re-scored
  2. 2026-11-06 12:41 UTCVendor advisory
  3. 2026-11-06 12:41 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  5. 2026-11-05 12:01 UTCEchelonGraph re-scored
  6. 2026-11-05 12:01 UTCVendor advisory
  7. 2026-11-05 12:01 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  9. 2026-11-04 11:21 UTCEchelonGraph re-scored
  10. 2026-11-04 11:21 UTCVendor advisory
  11. 2026-11-04 11:21 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  13. 2026-11-03 10:40 UTCEchelonGraph re-scored
  14. 2026-11-03 10:40 UTCVendor advisory
  15. 2026-11-03 10:40 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  17. 2026-11-02 10:00 UTCEchelonGraph re-scored
  18. 2026-11-02 10:00 UTCVendor advisory
  19. 2026-11-02 10:00 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  21. 2026-11-01 09:20 UTCEchelonGraph re-scored
  22. 2026-11-01 09:20 UTCVendor advisory
  23. 2026-11-01 09:20 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  25. 2026-10-31 08:41 UTCEchelonGraph re-scored
  26. 2026-10-31 08:41 UTCVendor advisory
  27. 2026-10-31 08:40 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  28. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  29. 2026-10-30 08:00 UTCEchelonGraph re-scored
  30. 2026-10-30 08:00 UTCVendor advisory
  31. 2026-10-30 08:00 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  32. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  33. 2026-10-29 07:21 UTCEchelonGraph re-scored
  34. 2026-10-29 07:21 UTCVendor advisory
  35. 2026-10-29 07:20 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  36. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  37. 2026-10-28 06:40 UTCEchelonGraph re-scored
  38. 2026-10-28 06:40 UTCVendor advisory
  39. 2026-10-28 06:40 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  40. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  41. 2026-10-27 06:01 UTCEchelonGraph re-scored
  42. 2026-10-27 06:01 UTCVendor advisory
  43. 2026-10-27 06:00 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  44. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  45. 2026-10-26 01:15 UTCEchelonGraph re-scored
  46. 2026-10-26 01:15 UTCVendor advisory
  47. 2026-10-26 01:15 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  48. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  49. 2026-10-25 14:24 UTCEchelonGraph re-scored
  50. 2026-10-25 00:35 UTCEchelonGraph re-scored
  51. 2026-10-25 00:35 UTCVendor advisory
  52. 2026-10-25 00:35 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  54. 2026-10-23 23:56 UTCEchelonGraph re-scored
  55. 2026-10-23 23:56 UTCVendor advisory
  56. 2026-10-23 23:56 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  58. 2026-10-22 23:16 UTCEchelonGraph re-scored
  59. 2026-10-22 23:16 UTCVendor advisory
  60. 2026-10-22 23:15 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  62. 2026-10-21 22:35 UTCEchelonGraph re-scored
  63. 2026-10-21 22:35 UTCVendor advisory
  64. 2026-10-21 22:35 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  66. 2026-10-20 21:56 UTCEchelonGraph re-scored
  67. 2026-10-20 21:56 UTCVendor advisory
  68. 2026-10-20 21:56 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  70. 2026-10-19 21:16 UTCEchelonGraph re-scored
  71. 2026-10-19 21:16 UTCVendor advisory
  72. 2026-10-19 21:16 UTCGHSA enrichmentGHSA-9979-85jw-xp9m · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  74. 2026-10-18 20:12 UTCEchelonGraph re-scored
  75. 2026-10-18 20:12 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-4711?
CVE-2026-4711 is a critical-severity vulnerability; its CVE record was published on March 24, 2026. Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
When was the CVE record for CVE-2026-4711 published?
The CVE record for CVE-2026-4711 was published on March 24, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of June 17, 2026; the record at its source may have been updated since.
Is CVE-2026-4711 actively exploited?
CVE-2026-4711 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-4711?
CVE-2026-4711 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-4711?
A fix for CVE-2026-4711 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-4711 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-4711

Explore →

Is Your Infrastructure Affected by CVE-2026-4711?

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