CVE-2020-36327Known exploitationPublic exploitNetwork attack vector

Rogue gem installation via transitive source confusion

Published Apr 29, 2021 · Updated Aug 4, 2024

Dependency confusion in RubyGems Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 allows attackers to install rogue public gems. Bundler resolves a private gem’s transitive dependency by the highest available version instead of prioritizing the source block that supplied its parent gem. Exploitation requires a public gem sharing the private dependency’s name and a higher compatible version; installation executes its code in the Bundler user’s context.

CVSS severity8.8
High
EPSS probability6.31%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Dependency confusion in RubyGems Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 allows attackers to install rogue public gems. Bundler resolves a private gem’s transitive dependency by the highest available version instead of prioritizing the source block that supplied its parent gem. Exploitation requires a public gem sharing the private dependency’s name and a higher compatible version; installation executes its code in the Bundler user’s context.

The record

CVE
CVE-2020-36327
Published
Apr 29, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1195.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3NIST NVDAV:N/AC:M/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

T1195.001Compromise Software Dependencies and Development Tools

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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