Exploitation evidence
Known exploited · CISA KEV listed
Added 2021-11-03. Ransomware campaign use: Unknown.
CISA required action: Apply updates per vendor instructions.
CISA due date: 2022-05-03. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
Mozilla / Firefox ESR
Default status: Not specified
- affected: unspecified to < 68.4.1 (custom)
Mozilla / Thunderbird
Default status: Not specified
- affected: unspecified to < 68.4.1 (custom)
Mozilla / Firefox
Default status: Not specified
- affected: unspecified to < 72.0.1 (custom)
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
CVE Program record ↗ · Download tracked evidence as JSON
- https://www.mozilla.org/security/advisories/mfsa2020-04/
- https://www.mozilla.org/security/advisories/mfsa2020-03/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1607443
- https://security.gentoo.org/glsa/202003-02
- https://usn.ubuntu.com/4335-1/
- http://packetstormsecurity.com/files/162568/Firefox-72-IonMonkey-JIT-Type-Confusion.html
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-17026
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.46311,
"percentile": 0.98835
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.46311,
"percentile": 0.98827
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.46311,
"percentile": 0.98825
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.46311,
"percentile": 0.98824
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.46311,
"percentile": 0.98823
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.46311,
"percentile": 0.98823
}06 Nov 2026, 12:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
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"datePublished": "2020-03-02T04:05:03.000Z",
"dateReserved": "2019-09-30T00:00:00.000Z",
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}05 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.46311,
"percentile": 0.98821
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.46311,
"percentile": 0.9882
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.46311,
"percentile": 0.98819
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.46311,
"percentile": 0.98818
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2019-17026",
"cwes": [
"CWE-843"
],
"dateAdded": "2021-11-03",
"dueDate": "2022-05-03",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Unknown",
"notes": "https://nvd.nist.gov/vuln/detail/CVE-2019-17026",
"product": "Firefox and Thunderbird",
"requiredAction": "Apply updates per vendor instructions.",
"shortDescription": "Mozilla Firefox and Thunderbird contain a type confusion vulnerability due to incorrect alias information in the IonMonkey JIT compiler when setting array elements.",
"vendorProject": "Mozilla",
"vulnerabilityName": "Mozilla Firefox And Thunderbird Type Confusion Vulnerability"
}