CVE-2026-4688

CRITICALNVD 10.010.0
EchelonGraph scoreMEDIUM confidence

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

Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-03-24. NVD baseline CVSS 10.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this week
10.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 10.0Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS v3
10.0
EG Score
10.0CRITICALmedium confidence
EG Risk
45
EG Risk 45/100

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)
Severity100% × 45%
Impact severity (EG Severity): CVSS 10.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (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.
EPSS PROB
0.5%
EPSS %ILE
43rd
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 (10.0): severity, escalated by confirmed exploitation. This CVE's 10.0 is its impact severity (EG Severity), not escalated.

EG Severity
10.0 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-18). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

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

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (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

July 15, 2026

Advisory Details (10)

Auto-updated Oct 15, 2026
Patch available. Sources: redhat.
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:6342
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:6188
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:5932
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:5931
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:5930
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

2016373 - (CVE-2026-4688) DocAccessibleParent::AddChildDoc OOP Child-Doc Rebind UAF

https://bugzilla.mozilla.org/show_bug.cgi?id=2016373

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_62026-04-15redhat
redhatthunderbird-0:140.9.0-1.el10_02026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_82026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_22026-04-15redhat
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_02026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_42026-04-15redhat
redhatfirefox-0:140.9.0-1.el8_82026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_22026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_42026-04-13redhat
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.el8_42026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_62026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_62026-04-13redhat
redhatfirefox-0:140.9.0-1.el10_02026-04-13redhat
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.

Affected Packages

(8 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr102.1.0esr-1 ... 91.9.1esr-1~deb9u1 (255 versions)
  • every version up to 140.9.0esr-1~deb11u1: fixed in 140.9.0esr-1~deb11u1
—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (306 versions)
  • every version up to 1:140.9.0esr-1~deb11u1: fixed in 1:140.9.0esr-1~deb11u1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr102.11.0esr-1 ... 140.8.0esr-1~deb13u1 (161 versions)
  • every version up to 140.9.0esr-1~deb12u1: fixed in 140.9.0esr-1~deb12u1
—
thunderbird1:102.11.0-1 ... 1:140.9.0esr-1~deb11u1 (191 versions)
  • every version up to 1:140.9.0esr-1~deb12u1: fixed in 1:140.9.0esr-1~deb12u1
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr128.13.0esr-1 ... 140.8.0esr-1~deb13u1 (36 versions)
  • every version up to 140.9.0esr-1~deb13u1: fixed in 140.9.0esr-1~deb13u1
—
thunderbird1:128.13.0esr-1 ... 1:140.9.0esr-1~deb11u1 (46 versions)
  • every version up to 1:140.9.0esr-1~deb13u1: fixed in 1:140.9.0esr-1~deb13u1
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr128.13.0esr-1 ... 140.9.0esr-1~deb13u1 (39 versions)
  • every version up to 140.9.0esr-1: fixed in 140.9.0esr-1
—
thunderbird1:128.13.0esr-1 ... 1:140.9.0esr-1~deb13u1 (48 versions)
  • every version up to 1:140.9.0esr-1: fixed in 1:140.9.0esr-1
—

Weakness Classification(2)

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

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 25× in last 7d / 52× 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 it from the CNA feed. 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). Most recent first.

Showing the most recent 100 of 332 refreshes 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 232 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-10-19 13:46 UTCEG score recompute
  3. 2026-10-19 13:46 UTCVendor advisory
  4. 2026-10-19 13:46 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  5. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  6. 2026-10-18 14:07 UTCVendor advisory
  7. 2026-10-18 14:07 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  8. 2026-10-18 03:36 UTCEG score recompute
  9. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-10-17 14:29 UTCEG score recompute
  11. 2026-10-17 14:29 UTCVendor advisory
  12. 2026-10-17 14:29 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  13. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-10-16 14:52 UTCEG score recompute
  15. 2026-10-16 14:52 UTCVendor advisory
  16. 2026-10-16 14:51 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  17. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  18. 2026-10-15 15:13 UTCEG score recompute
  19. 2026-10-15 15:13 UTCVendor advisory
  20. 2026-10-15 15:13 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  21. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  22. 2026-10-14 09:36 UTCEG score recompute
  23. 2026-10-14 09:36 UTCVendor advisory
  24. 2026-10-14 09:36 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  25. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
Show 75 more
  1. 2026-10-13 07:16 UTCEG score recompute
  2. 2026-10-13 07:16 UTCVendor advisory
  3. 2026-10-13 07:16 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  4. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-10-12 16:02 UTCEG score recompute
  6. 2026-10-12 07:37 UTCVendor advisory
  7. 2026-10-12 07:37 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  8. 2026-10-11 19:45 UTCEG score recompute
  9. 2026-10-11 16:59 UTCEG score recompute
  10. 2026-10-11 14:24 UTCEG score recompute
  11. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  15. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  18. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  19. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  21. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  22. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  24. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-09-26 00:27 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  26. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  27. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  28. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  29. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  30. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  31. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  32. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  33. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  34. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  35. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  36. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  37. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  38. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  39. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  40. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  41. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  42. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  43. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  44. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  45. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  46. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  47. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  48. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  49. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  50. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  51. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  52. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  53. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  54. 2026-08-16 10:40 UTCEG score recompute
  55. 2026-08-16 10:40 UTCVendor advisory
  56. 2026-08-16 10:40 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  57. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  58. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  59. 2026-08-14 23:21 UTCVendor advisory
  60. 2026-08-14 23:21 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  61. 2026-08-14 19:42 UTCVendor advisory
  62. 2026-08-14 19:42 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  63. 2026-08-14 14:10 UTCVendor advisory
  64. 2026-08-14 14:10 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  65. 2026-08-14 10:31 UTCVendor advisory
  66. 2026-08-14 10:31 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  67. 2026-08-14 06:52 UTCEG score recompute
  68. 2026-08-14 06:52 UTCVendor advisory
  69. 2026-08-14 06:52 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  70. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  71. 2026-08-13 04:50 UTCVendor advisory
  72. 2026-08-13 04:50 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  73. 2026-08-13 01:11 UTCVendor advisory
  74. 2026-08-13 01:11 UTCGHSA enrichmentGHSA-7364-g429-cg4v · GitHub severity CRITICAL · GitHub CVSS 10.0
  75. 2026-08-12 21:32 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-4688?
CVE-2026-4688 is a critical-severity vulnerability; its CVE record was published on March 24, 2026. Sandbox escape due to use-after-free in the Disability Access APIs 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-2026-4688 published?
The CVE record for CVE-2026-4688 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 July 15, 2026; the record at its source may have been updated since.
Is CVE-2026-4688 actively exploited?
CVE-2026-4688 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-4688?
CVE-2026-4688 has a CVSS v3 base score of 10.0 (NVD).
How do I remediate CVE-2026-4688?
A fix for CVE-2026-4688 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-4688 are linked in the Vendor Advisories panel on this page.

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