How severe is CVE-2017-5949?

CVE-2017-5949 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-5949 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-2017-5949?

CVE-2017-5949 affects Apple Safari. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-5949?

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

When was CVE-2017-5949 published?

CVE-2017-5949 was published on 2017-04-03 and last updated on 2026-06-17.

CVE-2017-5949

CVE-2017-5949 is a critical-severity vulnerability in Apple Safari with a CVSS 3.x base score of 9.8. 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: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Apple Safari
Published: 2017-04-03
Last modified: 2026-06-17

Description

JavaScriptCore in WebKit, as distributed in Safari Technology Preview Release 22, allows remote attackers to cause a denial of service (heap-based out-of-bounds write and application crash) or possibly have unspecified other impact via crafted JavaScript code that triggers access to red-zone memory locations, related to jit/ThunkGenerators.cpp, llint/LowLevelInterpreter32_64.asm, and llint/LowLevelInterpreter64.asm.

Frequently asked questions

What is CVE-2017-5949?: JavaScriptCore in WebKit, as distributed in Safari Technology Preview Release 22, allows remote attackers to cause a denial of service (heap-based out-of-bounds write and application crash) or possibly have unspecified other impact via crafted JavaScript code that triggers access to red-zone memory locations, related to jit/ThunkGenerators.cpp, llint/LowLevelInterpreter32_64.asm, and llint/LowLevelInterpreter64.asm.
How severe is CVE-2017-5949?: CVE-2017-5949 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-5949 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-2017-5949?: CVE-2017-5949 affects Apple Safari. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-5949?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-5949 published?: CVE-2017-5949 was published on 2017-04-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apple:safari:22:*:*:*:technology_preview:*:*:*

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