CVE-2026-66298

HIGHNVD 8.88.8
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 0.3% (19th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3

Also known asEUVD-2026-53602 (ENISA EUVD)Source: ENISA EUVD

8.8EG
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: 0.3%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Origin Validation Error vulnerability in livebook-dev livebook allows untrusted notebook output JavaScript to trigger session-wide keyboard shortcuts, including forced evaluation of all cells and runtime restart.

Livebook's JS-view feature renders notebook-defined JavaScript inside a sandboxed, cross-origin iframe specifically because that JavaScript is untrusted. The trusted iframe shell in iframe/priv/static/iframe/v5.html forwards every keydown event fired in its own window to the parent page without consulting Event.isTrusted, so an event synthesized by the untrusted script through window.dispatchEvent is forwarded exactly as a genuine keystroke would be. The parent-side relay in assets/js/hooks/js_view.js reconstructs and re-dispatches it on the live page with no further validation, and because assets/js/hooks/session.js registers the global shortcut handler on the document in the capture phase, that handler acts on the replicated event regardless of how it was produced.

Sandboxed output JavaScript can therefore drive Livebook's session-wide keyboard shortcuts. Two of them reach LivebookWeb.SessionLive and execute immediately with no confirmation: the shortcut for queueing full evaluation runs every cell in the notebook, and the shortcut for reconnecting the runtime disconnects and reconnects it, discarding in-memory state. A third shortcut deletes the focused cell behind a confirmation dialog that the user can permanently dismiss, after which it too executes silently.

Forced full evaluation is the significant consequence, because it causes the notebook's own Elixir code to run without the user choosing to evaluate anything. A user who merely opens a notebook obtained from a third party, or reached from published documentation, can have its code executed on their runtime. Livebook also mirrors cell outputs to every connected client, so a malicious output triggers in a collaborator's browser as soon as it renders.

This issue affects livebook: from 0.5.0 before 0.18.7 and from 0.19.0 before 0.19.9.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 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
0.3%
EPSS %ILE
19th
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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS. 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, 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; 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.

The score's inputs: 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

August 5, 2026

Last Modified

November 10, 2026

Advisory Details (6)

Auto-updated Aug 5, 2026
Patch available. Sources: github, github_commit.
GitHub commit

commit 5980e5c6b710 (livebook-dev/livebook)

Fix landed in livebook-dev/livebook commit 5980e5c6b710 — awaiting tagged release

https://github.com/livebook-dev/livebook/commit/5980e5c6b71036806b3bf54101eb1d6c0f50f19c
GitHub commit

commit a552ce8f99ad (livebook-dev/livebook)

Fix landed in livebook-dev/livebook commit a552ce8f99ad — awaiting tagged release

https://github.com/livebook-dev/livebook/commit/a552ce8f99ad348ea37061394dc950a0cebdb33e
GitHub commit

commit 296318ffdfa6 (livebook-dev/livebook)

Fix landed in livebook-dev/livebook commit 296318ffdfa6 — awaiting tagged release

https://github.com/livebook-dev/livebook/commit/296318ffdfa6e5ed7b18ad8d5a5b2af90f3cd728
Web page

OSV - Open Source Vulnerabilities

https://osv.dev/vulnerability/EEF-CVE-2026-66298
GitHub advisoryMentions a patch (unverified)

JS-view sandboxed output can synthesize keyboard events to trigger unconfirmed global shortcuts (forced full evaluation / runtime restart) · Advisory · livebook-dev/livebook · GitHub

https://github.com/livebook-dev/livebook/security/advisories/GHSA-68c2-prqg-x62g

Affected Packages

(1 across 1 ecosystem)
Hex(1)
PackageVulnerable rangeFix by version rangeDependents
livebook0.10.0 ... 0.9.3 (70 versions)
  • 0.5.0 up to 0.18.7: fixed in 0.18.7
  • 0.19.0 up to 0.19.9: fixed in 0.19.9
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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 148 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 48 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:53 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  3. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  4. 2026-11-10 17:35 UTCEchelonGraph re-scored
  5. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  6. 2026-11-10 02:40 UTCEchelonGraph re-scored
  7. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  8. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  9. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  10. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  11. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  12. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  13. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  14. 2026-11-03 11:53 UTCEchelonGraph re-scored
  15. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  16. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  17. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  18. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  19. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  20. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  21. 2026-10-27 21:06 UTCEchelonGraph re-scored
  22. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  23. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  24. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  25. 2026-10-25 14:11 UTCEchelonGraph re-scored
Show 75 more
  1. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  2. 2026-10-23 21:29 UTCEchelonGraph re-scored
  3. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  4. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  5. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  6. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  7. 2026-10-20 09:07 UTCEchelonGraph re-scored
  8. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  9. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  10. 2026-10-18 03:21 UTCEchelonGraph re-scored
  11. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  12. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  13. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  14. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  15. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  16. 2026-10-13 10:58 UTCEchelonGraph re-scored
  17. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  18. 2026-10-12 15:46 UTCEchelonGraph re-scored
  19. 2026-10-11 19:31 UTCEchelonGraph re-scored
  20. 2026-10-11 16:46 UTCEchelonGraph re-scored
  21. 2026-10-11 14:07 UTCEchelonGraph re-scored
  22. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  23. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  24. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  25. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  26. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  27. 2026-10-06 23:36 UTCEchelonGraph re-scored
  28. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  29. 2026-10-05 19:32 UTCEchelonGraph re-scored
  30. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  31. 2026-10-04 23:29 UTCEchelonGraph re-scored
  32. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  33. 2026-10-04 05:57 UTCEchelonGraph re-scored
  34. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  35. 2026-10-03 01:07 UTCEchelonGraph re-scored
  36. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  37. 2026-10-02 09:51 UTCEchelonGraph re-scored
  38. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  39. 2026-10-01 02:14 UTCEchelonGraph re-scored
  40. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  41. 2026-09-29 06:12 UTCEchelonGraph re-scored
  42. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  43. 2026-09-27 17:38 UTCEchelonGraph re-scored
  44. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  45. 2026-09-25 04:29 UTCEchelonGraph re-scored
  46. 2026-09-23 23:40 UTCEchelonGraph re-scored
  47. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  48. 2026-09-23 00:20 UTCEchelonGraph re-scored
  49. 2026-09-22 01:23 UTCEchelonGraph re-scored
  50. 2026-09-20 20:46 UTCEchelonGraph re-scored
  51. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  52. 2026-09-20 02:17 UTCEchelonGraph re-scored
  53. 2026-09-19 03:20 UTCEchelonGraph re-scored
  54. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  55. 2026-09-18 03:14 UTCEchelonGraph re-scored
  56. 2026-09-17 01:04 UTCEchelonGraph re-scored
  57. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  58. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  59. 2026-09-15 16:11 UTCEchelonGraph re-scored
  60. 2026-09-14 02:46 UTCEchelonGraph re-scored
  61. 2026-09-12 16:33 UTCEchelonGraph re-scored
  62. 2026-09-11 17:45 UTCEchelonGraph re-scored
  63. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  64. 2026-09-10 18:06 UTCEchelonGraph re-scored
  65. 2026-09-09 06:18 UTCEchelonGraph re-scored
  66. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  67. 2026-09-07 18:11 UTCEchelonGraph re-scored
  68. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  69. 2026-09-06 17:17 UTCEchelonGraph re-scored
  70. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  71. 2026-09-05 18:24 UTCEchelonGraph re-scored
  72. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  73. 2026-09-05 03:44 UTCEchelonGraph re-scored
  74. 2026-09-04 09:26 UTCEchelonGraph re-scored
  75. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 6th percentile

Frequently asked(5)

What is CVE-2026-66298?
CVE-2026-66298 is a high-severity vulnerability; its CVE record was published on August 5, 2026. Origin Validation Error vulnerability in livebook-dev livebook allows untrusted notebook output JavaScript to trigger session-wide keyboard shortcuts, including forced evaluation of all cells and runtime restart. Livebook's JS-view feature renders notebook-defined JavaScript inside a sandboxed,…
When was the CVE record for CVE-2026-66298 published?
The CVE record for CVE-2026-66298 was published on August 5, 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 November 10, 2026; the record at its source may have been updated since.
Is CVE-2026-66298 actively exploited?
CVE-2026-66298 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (19th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66298?
CVE-2026-66298 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-66298?
A fix for CVE-2026-66298 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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