CVE-2020-36327: Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 sometimes chooses a dependency source based on the high

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HIGH 8.8WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2020-36327 is a high-severity flaw (CVSS 8.8) affecting bundler, fedora, package manager configurations. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 sometimes chooses a dependency source based on the highest gem version number, which means that a rogue gem found at a public source may be chosen, even if the intended choice was a private gem that is a dependency of another private gem that is explicitly depended on by the application. NOTE: it is not correct to use CVE-2021-24105 for every "Dependency Confusion" issue in every product.

Why this priority

High severity
EPSS top 6%: very likely to be exploited
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	6.3% (top 6%)
CISA exploited list	No
Published	2021-04-29
Last modified	2026-10-08

Publisher (CNA): MITRE · Vendor: bundler · fedoraproject · microsoft

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-04-29 03:15 UTCPublished CVE record published
2026-10-08 21:17 UTCUpdated Record last modified

bundler bundler UPGRADE

Affected: >= 1.16.0 and < 2.2.10 · >= 2.2.11 and <= 2.2.16

Fixed in: 2.2.10

Safe to downgrade to: a release before 1.16.0

1. Check installed version

apt-cache policy bundler || rpm -q bundler || bundler --version

2. UPGRADE to 2.2.10 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade bundler

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade bundler

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.16.0 (Debian / Ubuntu)

apt-cache madison bundler sudo apt install bundler=<VERSION_BEFORE_1.16.0> sudo apt-mark hold bundler

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list bundler sudo dnf downgrade bundler-<VERSION_BEFORE_1.16.0> sudo dnf versionlock add bundler

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

fedoraproject fedora MITIGATE

Affected: 34

Fixed in: no fixed release known

Safe to downgrade to: a release before 34

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft package manager configurations MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy package-manager-configurations || rpm -q package-manager-configurations || package-manager-configurations --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-36327?

bundler: upgrade to 2.2.10; fedora: mitigate or apply the listed mitigation; package manager configurations: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-36327 being exploited?

CVE-2020-36327 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-36327 affect?

CVE-2020-36327 affects bundler, fedora, package manager configurations. Severity is high (CVSS 8.8). Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 sometimes chooses a dependency source based on the highest gem version number, which means that a rogue gem found at a public source may be chosen, even if the intended choice was a pri

How urgent is CVE-2020-36327?

Priority 64/100. High severity; EPSS top 6%: very likely to be exploited; Public exploit reference; On your watchlist

Related CVEs

CVE-2021-43809 MEDIUM 6.7 UPGRADE `Bundler` is a package for managing application dependencies in Ruby

References

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