How severe is CVE-2016-2339?

CVE-2016-2339 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-2016-2339 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-2339?

CVE-2016-2339 primarily affects Ruby-lang Ruby. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-2339?

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-2016-2339 published?

CVE-2016-2339 was published on 2017-01-06 and last updated on 2026-06-17.

CVE-2016-2339

CVE-2016-2339 is a critical-severity vulnerability in Ruby-lang Ruby 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-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Ruby-lang Ruby
Published: 2017-01-06
Last modified: 2026-06-17

Description

An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby. In Fiddle::Function.new "initialize" heap buffer "arg_types" allocation is made based on args array length. Specially constructed object passed as element of args array can increase this array size after mentioned allocation and cause heap overflow.

Frequently asked questions

What is CVE-2016-2339?: An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby. In Fiddle::Function.new "initialize" heap buffer "arg_types" allocation is made based on args array length. Specially constructed object passed as element of args array can increase this array size after mentioned allocation and cause heap overflow.
How severe is CVE-2016-2339?: CVE-2016-2339 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-2016-2339 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-2339?: CVE-2016-2339 primarily affects Ruby-lang Ruby. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-2339?: 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-2016-2339 published?: CVE-2016-2339 was published on 2017-01-06 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:ruby-lang:ruby:2.2.2:*:*:*:*:*:*:*
cpe:2.3:a:ruby-lang:ruby:2.3.0:*:*:*:*:*:*:*

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