How severe is CVE-2016-4121?

CVE-2016-4121 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-2016-4121 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-4121?

CVE-2016-4121 primarily affects Adobe Flash Player. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-4121?

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-2016-4121 published?

CVE-2016-4121 was published on 2016-06-16 and last updated on 2026-06-17.

CVE-2016-4121

CVE-2016-4121 is a critical-severity vulnerability in Adobe Flash Player with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 10% places it in the 95th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-416.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 10% (95th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-416
Affected product: Adobe Flash Player
Published: 2016-06-16
Last modified: 2026-06-17

Description

Use-after-free vulnerability in Adobe Flash Player before 18.0.0.352 and 19.x through 21.x before 21.0.0.242 on Windows and OS X and before 11.2.202.621 on Linux allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-1097, CVE-2016-1106, CVE-2016-1107, CVE-2016-1108, CVE-2016-1109, CVE-2016-1110, CVE-2016-4108, and CVE-2016-4110.

Frequently asked questions

What is CVE-2016-4121?: Use-after-free vulnerability in Adobe Flash Player before 18.0.0.352 and 19.x through 21.x before 21.0.0.242 on Windows and OS X and before 11.2.202.621 on Linux allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-1097, CVE-2016-1106, CVE-2016-1107, CVE-2016-1108, CVE-2016-1109, CVE-2016-1110, CVE-2016-4108, and CVE-2016-4110.
How severe is CVE-2016-4121?: CVE-2016-4121 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-2016-4121 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-4121?: CVE-2016-4121 primarily affects Adobe Flash Player. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-4121?: 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-2016-4121 published?: CVE-2016-4121 was published on 2016-06-16 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:adobe:flash_player:*:*:*:*:*:edge:*:*
cpe:2.3:a:adobe:flash_player:*:*:*:*:*:internet_explorer:*:*
cpe:2.3:a:adobe:flash_player:*:*:*:*:esr:*:*:*
cpe:2.3:a:adobe:air_sdk_\&_compiler:*:*:*:*:*:*:*:*
cpe:2.3:a:adobe:air_sdk:*:*:*:*:*:*:*:*
cpe:2.3:a:adobe:flash_player:*:*:*:*:*:*:*:*
cpe:2.3:a:adobe:flash_player:*:*:*:*:*:chrome:*:*
cpe:2.3:a:adobe:flash_player_desktop_runtime:*:*:*:*:*:*:*:*
cpe:2.3:a:adobe:air_desktop_runtime:*:*:*:*:*:*:*:*

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Other CWE-416 (Use After Free) vulnerabilities

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CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
CVE-2025-24085 — Critical (CVSS 10.0): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.3 and iPadOS 18.3,…
CVE-2024-43102 — Critical (CVSS 10.0): Concurrent removals of certain anonymous shared memory mappings by using the UMTX_SHM_DESTROY sub-request of…
CVE-2021-32495 — Critical (CVSS 10.0): Radare2 has a use-after-free vulnerability in pyc parser's get_none_object function. Attacker can read freed memory…

Browse all CWE-416 (Use After Free) vulnerabilities →