Skip to content
Fencer Intel
high 7.8

CVE-2011-4815 json

Ruby (aka CRuby) before 1.8.7-p357 computes hash values without restricting the ability to trigger hash collisions predictably, which allow…

published 2011-12-30 14 y ago modified 2026-06-16 4 mo ago also EUVD-2011-4733

cvss
7.8
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.1%
EPSS 4.1% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

Ruby (aka CRuby) before 1.8.7-p357 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.

Patch / fix

  • ruby4.0 hummingbird 1 4.0.0-33.3.hum1
  • ruby4.0-libs hummingbird 1 4.0.0-33.3.hum1
  • ruby4.0-bundled-gems hummingbird 1 4.0.0-33.3.hum1
  • ruby4.0-default-gems hummingbird 1 4.0.0-33.3.hum1
  • ruby3.3 hummingbird 1 3.3.10-23.1.hum1
  • ruby3.3-libs hummingbird 1 3.3.10-23.1.hum1
  • ruby3.3-bundled-gems hummingbird 1 3.3.10-23.1.hum1
  • ruby3.3-default-gems hummingbird 1 3.3.10-23.1.hum1

red hat advisories RHSA-2026:8838RHSA-2026:7305RHSA-2026:7307RHSA-2012:0070RHSA-2012:0069

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-4815 updated cvss 5.0

ruby: hash table collisions CPU usage DoS (oCERT-2011-003)

  • Red Hat Enterprise Linux (v. 5 server) ruby 1.8.5-22.el5_7.1, ruby-ri 1.8.5-22.el5_7.1, ruby-irb 1.8.5-22.el5_7.1, ruby-libs 1.8.5-22.el5_7.1, ruby-mode 1.8.5-22.el5_7.1, ruby-rdoc 1.8.5-22.el5_7.1, +1 more Red Hat Enterprise Linux AS version 4 irb 1.8.1-18.el4, ruby 1.8.1-18.el4, ruby-libs 1.8.1-18.el4, ruby-mode 1.8.1-18.el4, ruby-tcltk 1.8.1-18.el4 Red Hat Enterprise Linux Desktop (v. 5 client) ruby 1.8.5-22.el5_7.1, ruby-ri 1.8.5-22.el5_7.1, ruby-irb 1.8.5-22.el5_7.1, ruby-libs 1.8.5-22.el5_7.1, ruby-mode 1.8.5-22.el5_7.1, ruby-rdoc 1.8.5-22.el5_7.1, +1 more
    fixed: vendor fix RHSA-2012:0070
  • Red Hat Enterprise Linux Desktop (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2 Red Hat Enterprise Linux Desktop Optional (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2
    fixed: vendor fix RHSA-2012:0069
  • Red Hat Enterprise Linux Desktop version 4 irb 1.8.1-18.el4, ruby 1.8.1-18.el4, ruby-libs 1.8.1-18.el4, ruby-mode 1.8.1-18.el4, ruby-tcltk 1.8.1-18.el4 Red Hat Enterprise Linux ES version 4 irb 1.8.1-18.el4, ruby 1.8.1-18.el4, ruby-libs 1.8.1-18.el4, ruby-mode 1.8.1-18.el4, ruby-tcltk 1.8.1-18.el4
    fixed: vendor fix RHSA-2012:0070
  • Red Hat Enterprise Linux HPC Node (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2 Red Hat Enterprise Linux HPC Node Optional (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2 Red Hat Enterprise Linux Server (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2 Red Hat Enterprise Linux Server Optional (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2 Red Hat Enterprise Linux Workstation (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2 Red Hat Enterprise Linux Workstation Optional (v. 6) ruby 1.8.7.352-4.el6_2, ruby-ri 1.8.7.352-4.el6_2, ruby-irb 1.8.7.352-4.el6_2, ruby-libs 1.8.7.352-4.el6_2, ruby-rdoc 1.8.7.352-4.el6_2, ruby-tcltk 1.8.7.352-4.el6_2
    fixed: vendor fix RHSA-2012:0069
  • Red Hat Enterprise Linux WS version 4 irb 1.8.1-18.el4, ruby 1.8.1-18.el4, ruby-libs 1.8.1-18.el4, ruby-mode 1.8.1-18.el4, ruby-tcltk 1.8.1-18.el4
    fixed: vendor fix RHSA-2012:0070
  • Red Hat Hardened Images ruby3.4 3.4.8-31.1.hum1, ruby4.0 4.0.0-33.3.hum1, ruby3.3 3.3.10-23.1.hum1, ruby3.4-default-gems 3.4.8-31.1.hum1, ruby4.0-default-gems 4.0.0-33.3.hum1, ruby3.3-default-gems 3.3.10-23.1.hum1
    fixed: vendor fix RHSA-2026:7305
  • Red Hat RHEL Desktop Workstation (v. 5 client) ruby 1.8.5-22.el5_7.1, ruby-ri 1.8.5-22.el5_7.1, ruby-irb 1.8.5-22.el5_7.1, ruby-libs 1.8.5-22.el5_7.1, ruby-mode 1.8.5-22.el5_7.1, ruby-rdoc 1.8.5-22.el5_7.1, +1 more
    fixed: vendor fix RHSA-2012:0070

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.06% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 7.8 AV:N/AC:L/Au:N/C:N/I:N/A:C

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.