CVE-2011-4838

CVE-2011-4838 is a medium-severity vulnerability in Jruby with a CVSS 2.0 base score of 5.0. 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-400.

Key facts

Description

JRuby before 1.6.5.1 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table.

Frequently asked questions

What is CVE-2011-4838?
JRuby before 1.6.5.1 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table.
How severe is CVE-2011-4838?
CVE-2011-4838 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2011-4838 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-4838?
CVE-2011-4838 affects Jruby. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2011-4838?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-4838 published?
CVE-2011-4838 was published on 2011-12-30 and last updated on 2026-06-16.

References

Affected products (1)

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