CVE-2023-6866

HIGHNVD 8.88.8—

8.8

TypedArrays can be fallible and lacked proper exception handling. This could lead to abuse in other APIs which expect TypedArrays to always succeed. This vulnerability affects Firefox < 121.

CVSS v3: 8.8
EG Score: 8.8(medium)
EPSS: 78.5%
KEV: Not listed

Published

December 19, 2023

Last Modified

November 21, 2024

References (6)

security@mozillahttps://bugzilla.mozilla.org/show_bug.cgi?id=1849037
security@mozillahttps://security.gentoo.org/glsa/202401-10
security@mozillahttps://www.mozilla.org/security/advisories/mfsa2023-56/
af854a3a-2127-422b-91ae-364da2661108https://bugzilla.mozilla.org/show_bug.cgi?id=1849037
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202401-10
af854a3a-2127-422b-91ae-364da2661108https://www.mozilla.org/security/advisories/mfsa2023-56/

Patch Availability(1)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
ubuntu	firefox-mozsymbols (121.0+build1-0ubuntu0.20.04.1) @ focal	2026-05-24	ubuntu

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(1)

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

CWE-755Improper Handling of Exceptional Conditions

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

UbuntuUSN-6562-1MEDIUM
Firefox vulnerabilities

Data Freshness Timeline

(refreshed 9× in last 7d / 9× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 13:40 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:43 UTCepss_batch
2026-05-26 13:43 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-24 11:46 UTCEG score recompute
2026-05-24 11:46 UTCVendor advisory
2026-05-24 11:46 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2023-6866?

CVE-2023-6866 is a high vulnerability published on December 19, 2023. TypedArrays can be fallible and lacked proper exception handling. This could lead to abuse in other APIs which expect TypedArrays to always succeed. This vulnerability affects Firefox < 121.

When was CVE-2023-6866 disclosed?

CVE-2023-6866 was first published in the National Vulnerability Database on December 19, 2023, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2023-6866 actively exploited?

CVE-2023-6866 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 78.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2023-6866?

CVE-2023-6866 has a CVSS v3 base score of 8.8 (NVD).

How do I remediate CVE-2023-6866?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-6866, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-6866

Explore →

Is Your Infrastructure Affected by CVE-2023-6866?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2023-6866

Published

Last Modified

References (6)

Patch Availability(1)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-6866?

Same vendor

Same CWE

CVE-2023-6866

📅 Published

🔄 Last Modified

🔗 References (6)

Patch Availability(1)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-6866?

🔗 Related CVEs(same vendor + same CWE)

Same vendor

Same CWE

Published

Last Modified

References (6)

Frequently asked(5)

Related CVEs(same vendor + same CWE)