CVE-2011-5036

Exp

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.

Published: 2011-12-30 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2011-5036 is rated High Exploit Risk (69/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 4.02%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.74% over the last day, indicating growing attacker interest. Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2011-5036

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2011-5036

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.28% 4.02% +2.74%
2 2025-03-30 2.11% 1.28% -0.83%
3 2025-03-29 2.11%

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2011-5036

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2011-5036

GitHub Security Advisory for CVE-2011-5036

GHSA-v6j3-7jrw-hq2p · Severity: medium · Ecosystem: rubygems — Rack Gem Subject to Denial of Service via Hash Collisions

OS Trackers for CVE-2011-5036

vendor priority summary link
debian not yet assigned CVE-2011-5036 not yet assigned priority: Debian including 1 source packages (ruby-rack), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2011-5036
gentoo normal CVE-2011-5036: 1 GLSA(s) (201203-05), 1 atom(s) (dev-ruby/rack); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2011-5036
redhat medium https://access.redhat.com/security/cve/CVE-2011-5036
ubuntu medium CVE-2011-5036 medium priority: Ubuntu including 1 source packages (ruby-rack), 17 status rows across 17 suites (hardy, lucid, maverick, natty, oneiric, precise, quantal, raring, saucy, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): not-affected 10, DNE 5, ignored 1, released 1. https://ubuntu.com/security/CVE-2011-5036

Affected software / configurations for CVE-2011-5036

Vendor Product Version Raw CPE
rack_project rack <= 1.1.0 cpe:2.3:a:rack_project:rack:*:*:*:*:*:*:*:*
rack_project rack 1.2.0 cpe:2.3:a:rack_project:rack:1.2.0:*:*:*:*:*:*:*
rack_project rack 1.2.1 cpe:2.3:a:rack_project:rack:1.2.1:*:*:*:*:*:*:*
rack_project rack 1.2.2 cpe:2.3:a:rack_project:rack:1.2.2:*:*:*:*:*:*:*
rack_project rack 1.2.3 cpe:2.3:a:rack_project:rack:1.2.3:*:*:*:*:*:*:*
rack_project rack 1.2.4 cpe:2.3:a:rack_project:rack:1.2.4:*:*:*:*:*:*:*
rack_project rack 1.3.0 cpe:2.3:a:rack_project:rack:1.3.0:*:*:*:*:*:*:*
rack_project rack 1.3.1 cpe:2.3:a:rack_project:rack:1.3.1:*:*:*:*:*:*:*
rack_project rack 1.3.2 cpe:2.3:a:rack_project:rack:1.3.2:*:*:*:*:*:*:*
rack_project rack 1.3.3 cpe:2.3:a:rack_project:rack:1.3.3:*:*:*:*:*:*:*
rack_project rack 1.3.4 cpe:2.3:a:rack_project:rack:1.3.4:*:*:*:*:*:*:*
rack_project rack 1.3.5 cpe:2.3:a:rack_project:rack:1.3.5:*:*:*:*:*:*:*

References for CVE-2011-5036

cvelogic Threat Intelligence