CVE-2011-4838
JRuby before 1.6.5.1 computes hash values without restricting the ability to trigger hash...
CVE-2011-4838 is a medium vulnerability (CVSS 5.0) in Jruby, published December 30, 2011. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 4.20%, the 90th percentile. Fixed in jruby 1.5.6-4.
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.
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2011-4838- CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-400
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2011-4838- Updated
- 2026-11-02
EUVDEUVD-2011-4756 No score
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.
- Record
EUVD-2011-4756- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-cgqc-fqxr-q6r6 No score
JRuby before 1.6.5.1 computes hash values without restricting the ability to trigger hash...
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.
- Record
GHSA-cgqc-fqxr-q6r6- Weakness
- CWE-400
- Updated
- 2026-11-02
OSV No score
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.
- Record
CVE-2011-4838- Updated
- 2026-11-02
OSVDEBIAN-CVE-2011-4838 No score
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.
- Record
DEBIAN-CVE-2011-4838- Updated
- 2026-11-02
Affected products
Affected packages
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
nruns.com/_downloads/advisory28122011.pdf
exchange.xforce.ibmcloud.com/vulnerabilities/72019
jruby.org/2011/12/27/jruby-1-6-5-1.html
secunia.com/advisories/50084
kb.cert.org/vuls/id/903934
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rhn.redhat.com/errata/RHSA-2012-1232.html
archives.neohapsis.com/archives/bugtraq/2011-12/0181.html
security.gentoo.org/glsa/glsa-201207-06.xml
ocert.org/advisories/ocert-2011-003.html
nvd.nist.gov/vuln/detail/CVE-2011-4838
github.com/advisories/GHSA-cgqc-fqxr-q6r6
security-tracker.debian.org/tracker/CVE-2011-4838