How severe is CVE-2021-30749?

CVE-2021-30749 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-30749 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30749?

CVE-2021-30749 primarily affects Apple Safari. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30749?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-30749 published?

CVE-2021-30749 was published on 2021-09-08 and last updated on 2026-06-17.

CVE-2021-30749

CVE-2021-30749 is a high-severity vulnerability in Apple Safari with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.8
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Apple Safari
Published: 2021-09-08
Last modified: 2026-06-17

Description

Multiple memory corruption issues were addressed with improved memory handling. This issue is fixed in tvOS 14.6, iOS 14.6 and iPadOS 14.6, Safari 14.1.1, macOS Big Sur 11.4, watchOS 7.5. Processing maliciously crafted web content may lead to arbitrary code execution.

Frequently asked questions

What is CVE-2021-30749?: Multiple memory corruption issues were addressed with improved memory handling. This issue is fixed in tvOS 14.6, iOS 14.6 and iPadOS 14.6, Safari 14.1.1, macOS Big Sur 11.4, watchOS 7.5. Processing maliciously crafted web content may lead to arbitrary code execution.
How severe is CVE-2021-30749?: CVE-2021-30749 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-30749 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30749?: CVE-2021-30749 primarily affects Apple Safari. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30749?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-30749 published?: CVE-2021-30749 was published on 2021-09-08 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

More vulnerabilities in Apple Safari

CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2015-5780 — Critical (CVSS 10.0): The Safari Extensions implementation in Apple Safari before 9 does not require user confirmation before replacing an…
CVE-2014-1303 — Critical (CVSS 10.0): Heap-based buffer overflow in Apple Safari 7.0.2 allows remote attackers to execute arbitrary code and bypass a sandbox…
CVE-2014-1300 — Critical (CVSS 10.0): Unspecified vulnerability in Apple Safari 7.0.2 on OS X allows remote attackers to execute arbitrary code with root…
CVE-2011-3046 — Critical (CVSS 10.0): The extension subsystem in Google Chrome before 17.0.963.78 does not properly handle history navigation, which allows…
CVE-2010-3116 — Critical (CVSS 10.0): Multiple use-after-free vulnerabilities in WebKit, as used in Apple Safari before 4.1.3 and 5.0.x before 5.0.3, Google…

All CVEs affecting Apple Safari →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →