CVE-2011-5036
Rack Gem Subject to Denial of Service via Hash Collisions
CVE-2011-5036 is a medium vulnerability (CVSS 5.0) in Rack Project Rack, published December 30, 2011. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.87%, the 90th percentile. Fixed in rack 1.1.3.
- Severity
- 5.0 MediumCVSS 2.0, NVD
- Exploit chance
- 3.87%EPSS, 90th percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
1.1.3rack +10 more
Description
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
Exploit likelihood
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rackRubyGems | before 1.1.3 | 1.1.3 |
rackRubyGems | 1.2.0 up to 1.2.5 | 1.2.5 |
rackRubyGems | 1.3.0 up to 1.3.6 | 1.3.6 |
org.jruby:jruby-parentMaven | before 1.6.5.1 | 1.6.5.1 |
ruby-rackDebian:12 | before 1.4.0-1 | 1.4.0-1 |
ruby-rackDebian:13 | before 1.4.0-1 | 1.4.0-1 |
ruby-rackDebian:14 | before 1.4.0-1 | 1.4.0-1 |
librack-rubyDebian:6.0 From an advisory covering 4 CVEs | before 1.1.0-4+squeeze1, plus listed versions 1.1.0-4 | 1.1.0-4+squeeze1 |
rackRubyGems | before 1.1.3, plus listed versions 0.1.00.2.00.3.00.4.00.9.0 Show 7 moreShow less0.9.11.0.01.0.11.1.01.1.11.1.1.pre1.1.2 | 1.1.3 |
rackRubyGems | 1.2.0 up to 1.2.5, plus listed versions 1.2.11.2.21.2.31.2.4 | 1.2.5 |
rackRubyGems | 1.3.0 up to 1.3.6, plus listed versions 1.3.11.3.21.3.31.3.41.3.5 | 1.3.6 |
What each source reports
NVD Score used
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
- Record
CVE-2011-5036- CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-310
- Updated
- 2026-11-02
CVE ListNo score
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
- Record
CVE-2011-5036- Updated
- 2026-11-02
EUVDEUVD-2022-5298No score
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
- Record
EUVD-2022-5298- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-v6j3-7jrw-hq2pNo score
Rack Gem Subject to Denial of Service via Hash Collisions
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
- Record
GHSA-v6j3-7jrw-hq2p- Weakness
- CWE-328, CWE-400
- Updated
- 2026-11-02
OSVNo score
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
- Record
CVE-2011-5036- Updated
- 2026-11-02
OSVDEBIAN-CVE-2011-5036No score
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
- Record
DEBIAN-CVE-2011-5036- Updated
- 2026-11-02
OSVGHSA-v6j3-7jrw-hq2pNo score
Rack Gem Subject to Denial of Service via Hash Collisions
Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
- Record
GHSA-v6j3-7jrw-hq2p- Weakness
- CWE-328, CWE-400
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
nruns.com/_downloads/advisory28122011.pdf
gist.github.com/52bbc6b9cc19ce330829
kb.cert.org/vuls/id/903934
archives.neohapsis.com/archives/bugtraq/2011-12/0181.html
debian.org/security/2013/dsa-2783
ocert.org/advisories/ocert-2011-003.html
Show 6 moreShow less
nvd.nist.gov/vuln/detail/CVE-2011-5036
web.archive.org/web/20120201040317/http://jruby.org/2011/12/27/jruby-1-6-5-1
github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2011-5036.yml
security-tracker.debian.org/tracker/CVE-2011-5036