CVE-2021-30809

HIGHNVD 8.88.8—Elevated

8.8

A use after free issue was addressed with improved memory management. This issue is fixed in Safari 15, tvOS 15, watchOS 8, iOS 15 and iPadOS 15. Processing maliciously crafted web content may lead to arbitrary code execution.

CVSS v3: 8.8
EG Score: 8.8(medium)
EPSS: 60.2%
KEV: Not listed

Published

October 28, 2021

Last Modified

November 21, 2024

References (12)

product-security@applehttp://www.openwall.com/lists/oss-security/2021/12/20/6
product-security@applehttps://support.apple.com/en-us/HT212814
product-security@applehttps://support.apple.com/en-us/HT212815
product-security@applehttps://support.apple.com/en-us/HT212816
product-security@applehttps://support.apple.com/en-us/HT212819
product-security@applehttps://support.apple.com/kb/HT212869
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/12/20/6
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212814
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212815
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212816
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212819
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/kb/HT212869

Patch Availability(2)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
redhat	webkitgtk4-0:2.48.3-2.el7_9	2025-07-07	redhat
redhat	webkit2gtk3-0:2.34.6-1.el8	2022-05-10	redhat

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-416Use After Free

All Vendor Advisories

(2)

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.

Data Freshness Timeline

(refreshed 12× in last 7d / 20× 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.

2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

GitHub PoCseregonwar/CVE-2021-30809-OOM
First seen Aug 9, 2025
CVE-2021-30809 UAF use-after-free PoC
Open source ↗

Frequently asked(5)

What is CVE-2021-30809?

CVE-2021-30809 is a high vulnerability published on October 28, 2021. A use after free issue was addressed with improved memory management. This issue is fixed in Safari 15, tvOS 15, watchOS 8, iOS 15 and iPadOS 15. Processing maliciously crafted web content may lead to arbitrary code execution.

When was CVE-2021-30809 disclosed?

CVE-2021-30809 was first published in the National Vulnerability Database on October 28, 2021, 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-2021-30809 actively exploited?

CVE-2021-30809 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 60.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-30809?

CVE-2021-30809 has a CVSS v3 base score of 8.8 (NVD).

How do I remediate CVE-2021-30809?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-30809, 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-2021-30809

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CVE-2021-30809

Published

Last Modified

References (12)

Patch Availability(2)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Publicly available exploits

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-30809?

Same vendor

Same CWE

CVE-2021-30809

📅 Published

🔄 Last Modified

🔗 References (12)

Patch Availability(2)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Publicly available exploits

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-30809?

🔗 Related CVEs(same vendor + same CWE)

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References (12)

Frequently asked(5)

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