`CVE-2011-4838`

5.0 Medium Not applicable

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.

CWE-400 · Uncontrolled resource consumption

Exploitation Status

No public exploit

Nothing published shows this CVE being exploited, which is not the same as ruling it out. nothing published in 14 years.

CVSS E:U

CISA KEV not listed
CISA Vulnrichment no assessment published
Indexed PoC none indexed
EPSS 4.2% chance in 30 days

Waratek Defense Posture

Not applicable

Not a Java vulnerability. Outside ARMR's domain entirely.

Protection none
Action not-needed none
Review automated upstream-data
Record active

Decided by unmatched-product : No tracked product matched above, and none present at all

Finding Affected product (jruby/jruby) is not in our known products list

Decided by	`unmatched-product` : No tracked product matched above, and none present at all
Finding	Affected product (jruby/jruby) is not in our known products list

CVSS

5.0 v2.0 AV:N/AC:L/Au:N/C:N/I:N/A:P 1 metric

VRT selects the newest version's highest entry and publishes it as cvssScore, newest rather than largest because scores are not comparable across versions, and highest rather than first because the first entry is frequently a CNA placeholder scoring 0.0 over NVD's own analysis.

Version Score Band Vector Assigner Type

CVSS 2.0 5.0 no band published AV:N/AC:L/Au:N/C:N/I:N/A:P NVD Primary published

Version	Score	Band	Vector	Assigner	Type
CVSS 2.0	5.0	no band published	`AV:N/AC:L/Au:N/C:N/I:N/A:P`	NVD	Primary	published

Affected Software & Releases

🖥️ Product CPEs & Version Ranges

1 product(s) over 1 version claims (uncapped)

Source	Vendor	Product	Scheme	Affected Versions
nvd	jruby	jruby	generic	＜ 1.6.5.1

Source

Vendor

Product

Scheme

Affected Versions

nvd

jruby

generic

＜ 1.6.5.1

References

URL	Tags
http://archives.neohapsis.com/archives/bugtraq/2011-12/0181.html	Broken Link
http://jruby.org/2011/12/27/jruby-1-6-5-1.html	Vendor Advisory
http://rhn.redhat.com/errata/RHSA-2012-1232.html	Broken Link
http://secunia.com/advisories/47407	Third Party Advisory
http://secunia.com/advisories/50084	Third Party Advisory
http://security.gentoo.org/glsa/glsa-201207-06.xml	Third Party Advisory
http://www.kb.cert.org/vuls/id/903934	Third Party Advisory, US Government Resource
http://www.nruns.com/_downloads/advisory28122011.pdf	Third Party Advisory
http://www.ocert.org/advisories/ocert-2011-003.html	Third Party Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/72019	Third Party Advisory, VDB Entry

URL

Timeline

Published 2011-12-30 Last modified 2026-06-16

Published	2011-12-30	By the CVE Program.
NVD record modified	2026-06-16	NVD's own last-modified date for this record.

Published

2011-12-30

By the CVE Program.

NVD record modified

2026-06-16

NVD's own last-modified date for this record.

Pipeline policy audit (14 of 21 rules evaluated)

14 of 21 rules ran. The rest were never reached, because an earlier stage settled the CVE, a distinct claim from a rule that ran and found nothing.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? first match wins

1 rejected no-match CVE Program withdrawal of this identifier

scope: Is the vulnerability ARMR's to address? first match wins

2 armr-patch-file no-match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no-match An ARMR security-rule template on disk for this CVE

4 manual-classification no-match A researcher's recorded decision for this specific CVE

5 manual classification no-match Manual classification of this CVE in the legacy dataset

6 non-java-upstream no-match A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component no-match The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the native WebLogic proxy plug-in. Oracle gives these no CPE of their own and names them only in the description.

8 osv-maven no-match An OSV.dev record of this CVE affecting a package published to Maven Central

9 cna-maven-package no-match An affected Maven artifact named by the CNA itself

10 known-cpe-product no-match An NVD CPE naming a product ARMR tracks

11 cna-cpe-product no-match A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

12 oracle-advisory-family no-match A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

13 non-deployable-product no-match The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

14 unmatched-product decided it matched Not applicable No tracked product matched

disposition: What do we do about one that is? cumulative: every rule gets a turn

15 patch-hint not-reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

16 open-source-maven not-reached The affected package being open source on Maven, so the fix can be read

17 poc-derivable not-reached An indexed exploit to reverse-engineer, where there is no source to read

18 no-exploit not-reached With no fix path, a public exploit, or a CISA record of one

19 secure-rule-match not-reached A vulnerability class already blocked by an ARMR security rule

20 below-action-threshold not-reached Medium or Low severity, no KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

21 no-exploit-published not-reached A published working exploit for this candidate, not only a proof of concept, a forecast, or nothing at all

What the scope rules read

The products the record named, and whether known-products.yaml tracks them. This is the evidence the scope stage decided on.

Vendor Product Tracked CPE Source

jruby jruby not tracked cpe:2.3:a:jruby:jruby:*:*:*:*:*:*:*:*

Raw stored JSON document for this CVE ↗ · NVD ↗ · CVE.org ↗