CVE-2019-11720: Mozilla Firefox vulnerability

CVE-2019-11720: Some unicode characters are incorrectly treated as whitespace during the parsing of web content instead of...

Some unicode characters are incorrectly treated as whitespace during the parsing of web content instead of triggering parsing errors. This allows malicious code to then be processed, evading cross-site scripting (XSS) filtering. This vulnerability affects Firefox < 68.

UnknownCVSS not scoredNot KEV-listedUpdatedAug 4, 2024, 23:03 UTC (UTC+00:00)

Security readout for executives and security teams

Firefox before version 68 mishandled some Unicode characters while parsing web content. A malicious page could use that parsing gap to bypass XSS filtering and get script processed when it should have been rejected. Organizations are mainly exposed where users still run Firefox older than 68, including legacy managed desktops or old Linux distribution packages. Current supported Firefox deployments are less likely to be affected. Treat as a legacy-browser hygiene issue unless old Firefox remains in production. Prioritize remediation for shared workstations, kiosks, or unmanaged endpoints that may browse untrusted sites. Mitigation focus: Upgrade Firefox to version 68 or later where applicable.; Apply relevant Mozilla, Gentoo, or openSUSE security updates.; Retire unsupported browser versions from managed endpoints..

Prepared: Jun 6, 2026, 14:06 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record

Severity: Unknown
CVSS: Not scored
Known Exploited: No
Published: Jul 23, 2019, 13:17 UTC (UTC+00:00)

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors

0Timeline events

0ADP providers

4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

CVE List V5 sourceCVE List V5
https://www.mozilla.org/security/advisories/mfsa2019-21/CVE reference · x_refsource_MISC
https://bugzilla.mozilla.org/show_bug.cgi?id=1556230CVE reference · x_refsource_MISC
GLSA-201908-12CVE reference · vendor-advisory, x_refsource_GENTOO

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus

MozillaFirefoxunspecifiedListed

Weakness

CWE details

No CWE listed

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