How severe is CVE-2018-4266?

CVE-2018-4266 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-4266 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-4266?

CVE-2018-4266 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-2018-4266?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-4266 published?

CVE-2018-4266 was published on 2019-04-03 and last updated on 2026-06-17.

CVE-2018-4266

CVE-2018-4266 is a medium-severity vulnerability in Apple Safari with a CVSS 3.x base score of 5.9. 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-362.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Apple Safari
Published: 2019-04-03
Last modified: 2026-06-17

Description

A race condition was addressed with additional validation. This issue affected versions prior toiVersions prior to: OS 11.4.1, tvOS 11.4.1, watchOS 4.3.2, Safari 11.1.2, iTunes 12.8 for Windows, iCloud for Windows 7.6.

Frequently asked questions

What is CVE-2018-4266?: A race condition was addressed with additional validation. This issue affected versions prior toiVersions prior to: OS 11.4.1, tvOS 11.4.1, watchOS 4.3.2, Safari 11.1.2, iTunes 12.8 for Windows, iCloud for Windows 7.6.
How severe is CVE-2018-4266?: CVE-2018-4266 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-4266 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-4266?: CVE-2018-4266 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-2018-4266?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-4266 published?: CVE-2018-4266 was published on 2019-04-03 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
cpe:2.3:a:apple:icloud:*:*:*:*:*:*:*:*
cpe:2.3:a:apple:itunes:*:*:*:*:*:*:*:*

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-362 (Race Condition) vulnerabilities

CVE-2022-27626 — Critical (CVSS 10.0): A vulnerability regarding concurrent execution using shared resource with improper synchronization ('Race Condition')…
CVE-2015-8556 — Critical (CVSS 10.0): Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.
CVE-2014-0703 — Critical (CVSS 10.0): Cisco Wireless LAN Controller (WLC) devices 7.4 before 7.4.110.0 distribute Aironet IOS software with a race condition…
CVE-2010-1228 — Critical (CVSS 10.0): Multiple race conditions in the sandbox infrastructure in Google Chrome before 4.1.249.1036 have unspecified impact and…
CVE-2008-6598 — Critical (CVSS 10.0): Multiple race conditions in WANPIPE before 3.3.6 have unknown impact and attack vectors related to "bri restart logic."
CVE-2026-46137 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: fix potential…

Browse all CWE-362 (Race Condition) vulnerabilities →