CVE-2019-9792

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Weaponized
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 13%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
95.9%
KEV
Not listed

Published

April 26, 2019

Last Modified

November 25, 2025

Advisory Details (7)

Auto-updated Jul 6, 2026
Patch available. Sources: redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2019:1144
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2019:0966
generic

Packet Storm

http://packetstormsecurity.com/files/153106/Spidermonkey-IonMonkey-JS_OPTIMIZED_OUT-Value-Leak.html
generic

Security vulnerabilities fixed in Thunderbird 60.6 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2019-11/
generic

Security vulnerabilities fixed in Firefox ESR 60.6 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2019-08/
generic

Security vulnerabilities fixed in Firefox 66 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2019-07/
generic

1532599 - (CVE-2019-9792) Spidermonkey: IonMonkey leaks JS_OPTIMIZED_OUT magic value to script

https://bugzilla.mozilla.org/show_bug.cgi?id=1532599

Vendor Advisories for CVE-2019-9792(6)

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

Patch Availability(9)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntufirefox-testsuite (66.0+build3-0ubuntu0.18.10.1) @ cosmic2026-05-27ubuntu
ubuntuxul-ext-lightning (1:60.6.1+build2-0ubuntu0.16.04.1) @ xenial2026-05-27ubuntu
ubuntufirefox-testsuite (66.0.1+build1-0ubuntu0.14.04.1) @ trusty2026-05-27ubuntu
redhatthunderbird-0:60.6.1-1.el82019-05-13redhat
redhatfirefox-0:60.6.1-1.el82019-05-07redhat
redhatthunderbird-0:60.6.1-1.el6_102019-03-28redhat
redhatthunderbird-0:60.6.1-1.el7_62019-03-28redhat
redhatfirefox-0:60.6.0-3.el6_102019-03-20redhat
redhatfirefox-0:60.6.0-3.el7_62019-03-20redhat

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(2)

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

Additional Vendor Advisories

(3)

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 9× in last 7d / 42× 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.

  1. 2026-07-06 16:25 UTCEPSS rescore
  2. 2026-07-06 16:25 UTCEPSS rescore
  3. 2026-07-06 02:20 UTCEPSS rescore
  4. 2026-07-05 02:27 UTCEPSS rescore
  5. 2026-07-03 12:26 UTCOSV refresh
  6. 2026-07-01 15:03 UTCEPSS rescore
  7. 2026-07-01 15:03 UTCEPSS rescore
  8. 2026-06-30 23:20 UTCEPSS rescore
  9. 2026-06-30 23:20 UTCEPSS rescore
  10. 2026-06-29 14:04 UTCEPSS rescore
  11. 2026-06-29 14:04 UTCEPSS rescore
  12. 2026-06-28 14:05 UTCEPSS rescore
  13. 2026-06-28 04:54 UTCEPSS rescore
  14. 2026-06-28 04:54 UTCEPSS rescore
  15. 2026-06-27 03:06 UTCEPSS rescore
  16. 2026-06-25 13:47 UTCEPSS rescore
  17. 2026-06-25 13:47 UTCEPSS rescore
  18. 2026-06-24 14:03 UTCEPSS rescore
  19. 2026-06-24 14:03 UTCEPSS rescore
  20. 2026-06-23 21:31 UTCEPSS rescore
  21. 2026-06-23 21:31 UTCEPSS rescore
  22. 2026-06-21 01:57 UTCEPSS rescore
  23. 2026-06-21 01:57 UTCEPSS rescore
  24. 2026-06-19 19:23 UTCEPSS rescore
  25. 2026-06-19 19:23 UTCEPSS rescore
Show 43 more
  1. 2026-06-18 17:50 UTCEPSS rescore
  2. 2026-06-18 17:50 UTCEPSS rescore
  3. 2026-06-17 17:50 UTCEPSS rescore
  4. 2026-06-16 17:50 UTCEPSS rescore
  5. 2026-06-15 17:46 UTCEPSS rescore
  6. 2026-06-15 02:43 UTCOSV refresh
  7. 2026-06-14 23:15 UTCEPSS rescore
  8. 2026-06-14 23:15 UTCEPSS rescore
  9. 2026-06-13 22:58 UTCEPSS rescore
  10. 2026-06-12 23:09 UTCEPSS rescore
  11. 2026-06-12 23:09 UTCEPSS rescore
  12. 2026-06-11 13:58 UTCEPSS rescore
  13. 2026-06-10 22:16 UTCEPSS rescore
  14. 2026-06-10 22:16 UTCEPSS rescore
  15. 2026-06-10 13:19 UTCEPSS rescore
  16. 2026-06-07 15:23 UTCEPSS rescore
  17. 2026-06-07 15:23 UTCEPSS rescore
  18. 2026-06-06 13:45 UTCEPSS rescore
  19. 2026-06-06 13:45 UTCEPSS rescore
  20. 2026-06-05 22:45 UTCEPSS rescore
  21. 2026-06-04 13:10 UTCEPSS rescore
  22. 2026-06-04 13:10 UTCEPSS rescore
  23. 2026-06-02 20:11 UTCEPSS rescore
  24. 2026-06-02 20:11 UTCEPSS rescore
  25. 2026-06-01 13:50 UTCEPSS rescore
  26. 2026-06-01 13:50 UTCEPSS rescore
  27. 2026-05-31 22:29 UTCEPSS rescore
  28. 2026-05-31 22:29 UTCEPSS rescore
  29. 2026-05-31 00:14 UTCEPSS rescore
  30. 2026-05-31 00:14 UTCEPSS rescore
  31. 2026-05-29 13:42 UTCEPSS rescore
  32. 2026-05-28 13:43 UTCEPSS rescore
  33. 2026-05-28 13:43 UTCEPSS rescore
  34. 2026-05-27 20:05 UTCEG score recompute
  35. 2026-05-27 20:05 UTCVendor advisory
  36. 2026-05-27 20:05 UTCGHSA enrichment
  37. 2026-05-27 13:39 UTCEPSS rescore
  38. 2026-05-27 13:38 UTCEPSS rescore
  39. 2026-05-26 13:42 UTCEPSS rescore
  40. 2026-05-26 07:17 UTCEPSS rescore
  41. 2026-05-26 07:17 UTCEPSS rescore
  42. 2026-05-26 07:17 UTCEPSS rescore
  43. 2026-05-24 16:47 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-46939✓ verified
    First seen May 29, 2019

    Spidermonkey - IonMonkey Leaks JS_OPTIMIZED_OUT Magic Value to Script

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2019-9792?
CVE-2019-9792 is a critical vulnerability published on April 26, 2019. The IonMonkey just-in-time (JIT) compiler can leak an internal JSOPTIMIZEDOUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird <…
When was CVE-2019-9792 disclosed?
CVE-2019-9792 was first published in the National Vulnerability Database on April 26, 2019, with the most recent update on November 25, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2019-9792 actively exploited?
CVE-2019-9792 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 95.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2019-9792?
CVE-2019-9792 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2019-9792?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2019-9792, 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

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