CVE-2020-11020: Faye (NPM, RubyGem) versions greater than 0.5.0 and before 1.0.4, 1.1.3 and 1.2.5, has the potential for authe

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HIGH 8.5UPGRADEUPGRADE

CVE-2020-11020 is a high-severity flaw (CVSS 8.5) affecting faye, faye. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Faye (NPM, RubyGem) versions greater than 0.5.0 and before 1.0.4, 1.1.3 and 1.2.5, has the potential for authentication bypass in the extension system. The vulnerability allows any client to bypass checks put in place by server-side extensions, by appending extra segments to the message channel. It is patched in versions 1.0.4, 1.1.3 and 1.2.5.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.6% (top 25%)
CISA exploited list	No
Weakness	CWE-287
Published	2020-04-29
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: faye project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-04-29 18:15 UTCPublished CVE record published
2026-06-17 02:48 UTCUpdated Record last modified

faye project faye UPGRADE

Affected: > 0.5.0 and < 1.0.4 · >= 1.1.0 and < 1.1.3 · >= 1.2.0 and < 1.2.5

Fixed in: 1.0.4, 1.1.3, 1.2.5

Safe to downgrade to: a release before 1.1.0

1. Check installed version

npm ls faye

2. UPGRADE to 1.0.4

npm install faye@">=1.0.4"

3. If no update is available yet, DOWNGRADE to a release before 1.1.0

npm view faye versions npm install faye@"<1.1.0"

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.

faye project faye UPGRADE

Affected: > 0.5.0 and < 1.0.4 · >= 1.1.0 and < 1.1.3 · >= 1.2.0 and < 1.2.5

Fixed in: 1.0.4, 1.1.3, 1.2.5

Safe to downgrade to: a release before 1.1.0

1. Check installed version

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

2. UPGRADE to 1.0.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade faye

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 1.1.0 (Debian / Ubuntu)

apt-cache madison faye sudo apt install faye=<VERSION_BEFORE_1.1.0> sudo apt-mark hold faye

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

dnf --showduplicates list faye sudo dnf downgrade faye-<VERSION_BEFORE_1.1.0> sudo dnf versionlock add faye

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.

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-2020-11020?

faye: upgrade to 1.0.4, 1.1.3, 1.2.5; faye: upgrade to 1.0.4, 1.1.3, 1.2.5. Exact commands for each OS are on this page.

Is CVE-2020-11020 being exploited?

CVE-2020-11020 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-2020-11020 affect?

CVE-2020-11020 affects faye, faye. Severity is high (CVSS 8.5). Faye (NPM, RubyGem) versions greater than 0.5.0 and before 1.0.4, 1.1.3 and 1.2.5, has the potential for authentication bypass in the extension system. The vulnerability allows any client to bypass checks put in place by server-side extensi

How urgent is CVE-2020-11020?

Priority 54/100. High severity; Public exploit reference

Related CVEs

CVE-2020-15134 HIGH 8.0 UPGRADE Faye before version 1.4.0, there is a lack of certification validation in TLS handshakes

References

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