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VULNERABILITIES

CVE-2026-109721 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

Description

Incorrect boundary conditions in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

Metrics

CVSS 3.x Severity and Vector Strings:

NDDVolerionCVSS-B:5.4 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CNA: CISA-ADPCVSS-B:5.4 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=2074161 [email protected]Issue TrackingPermission RequiredVendor
https://www.mozilla.org/security/advisories/mfsa2026-106/ [email protected]AdvisoryBundleVendor
https://www.mozilla.org/security/advisories/mfsa2026-108/ [email protected]AdvisoryBundleVendor
https://www.mozilla.org/security/advisories/mfsa2026-109/ [email protected]AdvisoryBundleVendor
https://www.mozilla.org/security/advisories/mfsa2026-110/ [email protected]AdvisoryBundleVendor

Weakness Enumeration

CWE-IDCWE NameSource
CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferCISA-ADP

Affected Products

ProductVersions
Mozilla Firefox
All versions

CPE

  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

Remediation

  • Upgrade: 158moderate effort
Mozilla Firefox ESR
All versions

CPE

  • cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*

Remediation

  • Upgrade: 153.5moderate effort
Mozilla Thunderbird
All versions

CPE

  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

Remediation

  • Upgrade: 158moderate effort
  • Upgrade: 153.5moderate effort

Change History

3 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-109721
NVD Published Date:
Oct 13, 2026
NVD Last Modified:
Oct 19, 2026
Source:
[email protected]
CVE-2026-109721 Details - Not Deferred