How severe is CVE-2022-30123?

CVE-2022-30123 has a CVSS score of 10/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-30123?

CVE-2022-30123 affects the following packages: rack (RubyGems), rack (RubyGems), rack (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2022-30123?

Update rack to 2.0.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-30123 is resolved across your whole dependency graph.

How do I detect CVE-2022-30123 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2022-30123 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2022-30123 actively exploited in the wild?

No public exploit code has been indexed for CVE-2022-30123 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2022-30123?

CVE-2022-30123 has an EPSS (Exploit Prediction Scoring System) score of 2.0%, placing it in the 80th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2022-30123?

CVE-2022-30123 is classified as CWE-150 (CWE-150). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2022-30123 published, and has it been updated?

CVE-2022-30123 was published on December 5, 2022 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎

💎 RubyGems

Not in CISA KEV

CRITICAL severity

CVE-2022-30123 — rack

CRITICALFix: rack/rack@b426cc2

CVE-2022-30123 is a critical-severity (CVSS 10) CWE-150 vulnerability in rack. A fix is available for rack — see the affected versions and patch details below.

Possible shell escape sequence injection vulnerability in Rack

Also known asGHSA-wq4h-7r42-5hrr

Published

Dec 5, 2022

Updated

Oct 28, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs80th percentile — riskier than 80% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

3 pkgs affected

💎rack💎rack💎rack

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

There is a possible shell escape sequence injection vulnerability in the Lint and CommonLogger components of Rack. This vulnerability has been assigned the CVE identifier CVE-2022-30123.

Versions Affected: All. Not affected: None Fixed Versions: 2.0.9.1, 2.1.4.1, 2.2.3.1

Impact

Carefully crafted requests can cause shell escape sequences to be written to the terminal via Rack's Lint middleware and CommonLogger middleware. These escape sequences can be leveraged to possibly execute commands in the victim's terminal.

Impacted applications will have either of these middleware installed, and vulnerable apps may have something like this:

use Rack::Lint

use Rack::CommonLogger

All users running an affected release should either upgrade or use one of the workarounds immediately.

Workarounds

Remove these middleware from your application

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`rack`	all versions	2.0.9.1`bundle update rack --conservative`
💎RubyGems	`rack`	≥ 2.1&&< 2.1.4.1	2.1.4.1`bundle update rack --conservative`
💎RubyGems	`rack`	≥ 2.2&&< 2.2.3.1	2.2.3.1`bundle update rack --conservative`

Affected Products

2 products · 4 configurations

debian linuxdebian

1 version

11.0

Application

rackrack_project

≥ 2.2.0 && < 2.2.3.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rack to 2.0.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-30123 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

- Because Red Hat OpenStack Platform 13.0 Operational Tools packaged the flawed code, but does not use its functionality, its Impact has been reduced to 'Low'. - To exploit this vulnerability, applications should have either of these middlewares 'Lint' or 'CommonLogger' installed, and vulnerable apps may have…

Product	Fixed in	Advisory
Logging subsystem for Red Hat OpenShift 5.4	`openshift-logging/fluentd-rhel8:v1.14.5-51`	RHSA-2023:0632
Red Hat Enterprise Linux 7	`pcs-0:0.9.169-3.el7_9.3`	RHSA-2022:7343
Red Hat Gluster Storage 3.5 for RHEL 7	`rubygem-rack-0:2.2.4-1.el7rhgs`	RHSA-2023:1486

Frequently Asked Questions

There is a possible shell escape sequence injection vulnerability in the Lint and CommonLogger components of Rack. This vulnerability has been assigned the CVE identifier CVE-2022-30123. Versions Affected: All. Not affected: None Fixed Versions: 2.0.9.1, 2.1.4.1, 2.2.3.1 ## Impact Carefully crafted requests can cause shell escape sequences to be written to the terminal via Rack's Lint middleware and CommonLogger middleware. These escape sequences can be leveraged to possibly execute commands in the victim's terminal. Impacted applications will have either of these middleware in