CVE-2026-12303

MEDIUMPre-NVD 4.34.3—Trending — 4 sources updated this week

4.3

Information disclosure due to incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

CVSS v3: 4.3
EG Score: 4.3(high)
EPSS: 12.5%
KEV: Not listed

Published

June 16, 2026

Last Modified

June 16, 2026

Advisory Details (3)

Auto-updated Jun 16, 2026

No patch confirmed yet.

generic

Security Vulnerabilities fixed in Thunderbird 152 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-60/

generic

Security Vulnerabilities fixed in Firefox 152 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-57/

generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2034608

Vendor Advisories for CVE-2026-12303(1)

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

GHSA-mx8m-2338-6rh3
GitHub Security AdvisoriesMedium
Information disclosure due to incorrect boundary conditions in the Graphics: WebGPU component....

Weakness Classification(1)

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

CWE-125Out-of-bounds Read

Data Freshness Timeline

(refreshed 14× in last 7d / 14× 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.

2026-06-21 14:56 UTCEPSS rescore
2026-06-21 14:56 UTCEPSS rescore
2026-06-21 01:59 UTCEPSS rescore
2026-06-21 01:59 UTCEPSS rescore
2026-06-20 19:27 UTCEG score recompute
2026-06-20 19:27 UTCGHSA enrichment
2026-06-19 19:25 UTCEPSS rescore
2026-06-19 19:03 UTCEG score recompute▲ 4.30
2026-06-19 19:03 UTCGHSA enrichment
2026-06-18 17:52 UTCEPSS rescore
2026-06-17 17:53 UTCEPSS rescore
2026-06-16 15:47 UTCNVD updateCVSS v3 → 4.3 · severity → MEDIUM
2026-06-16 13:49 UTCEG score recompute
2026-06-16 13:46 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-12303?

CVE-2026-12303 is a medium vulnerability published on June 16, 2026. Information disclosure due to incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

When was CVE-2026-12303 disclosed?

CVE-2026-12303 was first published in the National Vulnerability Database on June 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-12303 actively exploited?

CVE-2026-12303 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 12.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-12303?

CVE-2026-12303 has a CVSS v3.1 base score of 4.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).

How do I remediate CVE-2026-12303?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12303, 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

Explore the affected products and dependency analysis for CVE-2026-12303

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CVE-2026-12303

📅 Published

🔄 Last Modified

📋 Advisory Details (3)

Security Vulnerabilities fixed in Thunderbird 152 — Mozilla

Security Vulnerabilities fixed in Firefox 152 — Mozilla

Access Denied

📣 Vendor Advisories for CVE-2026-12303(1)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-12303?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

Advisory Details (3)

Vendor Advisories for CVE-2026-12303(1)

Frequently asked(5)

Related CVEs(same CWE)