How severe is GHSA-3h57-hmj3-gj3p?

GHSA-3h57-hmj3-gj3p has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-3h57-hmj3-gj3p?

GHSA-3h57-hmj3-gj3p affects the following packages: rack (RubyGems), rack (RubyGems), rack (RubyGems), rack (RubyGems). Ecosystems affected: RubyGems.

How do I fix GHSA-3h57-hmj3-gj3p?

Update rack to 2.0.9.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3h57-hmj3-gj3p is resolved across your whole dependency graph.

How do I detect GHSA-3h57-hmj3-gj3p 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 GHSA-3h57-hmj3-gj3p if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is GHSA-3h57-hmj3-gj3p actively exploited in the wild?

No public exploit code has been indexed for GHSA-3h57-hmj3-gj3p 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 GHSA-3h57-hmj3-gj3p?

GHSA-3h57-hmj3-gj3p has an EPSS (Exploit Prediction Scoring System) score of 1.8%, placing it in the 79th 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 GHSA-3h57-hmj3-gj3p?

GHSA-3h57-hmj3-gj3p is classified as Uncontrolled Resource Consumption (CWE-400), CWE-770 (CWE-770). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-3h57-hmj3-gj3p published, and has it been updated?

GHSA-3h57-hmj3-gj3p was published on March 8, 2023 and was last updated on February 13, 2025. 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

HIGH severity

Rack has possible DoS Vulnerability in Multipart MIME parsingGHSA-3h57-hmj3-gj3p

HIGH

GHSA-3h57-hmj3-gj3p is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in rack. A fix is available for rack — see the affected versions and patch details below.

Also known asCVE-2023-27530

Published

Mar 8, 2023

Updated

Feb 13, 2025

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-3h57-hmj3-gj3p.

EPSS Exploitation Probability

via FIRST.org ↗

1.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs79th percentile — riskier than 79% 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

4 pkgs affected

💎rack💎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 DoS vulnerability in the Multipart MIME parsing code in Rack. This vulnerability has been assigned the CVE identifier CVE-2023-27530.

Versions Affected: All. Not affected: None Fixed Versions: 3.0.4.2, 2.2.6.3, 2.1.4.3, 2.0.9.3

Impact

The Multipart MIME parsing code in Rack limits the number of file parts, but does not limit the total number of parts that can be uploaded. Carefully crafted requests can abuse this and cause multipart parsing to take longer than expected.

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

Workarounds

A proxy can be configured to limit the POST body size which will mitigate this issue.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`rack`	all versions	2.0.9.3`bundle update rack --conservative`
💎RubyGems	`rack`	≥ 2.1.0&&< 2.1.4.3	2.1.4.3`bundle update rack --conservative`
💎RubyGems	`rack`	≥ 2.2.0&&< 2.2.6.3	2.2.6.3`bundle update rack --conservative`
💎RubyGems	`rack`	≥ 3.0.0&&< 3.0.4.2	3.0.4.2`bundle update rack --conservative`

Affected Products

2 products · 6 configurations

debian linuxdebian

2 versions

10.011.0

Application

rackrack

≥ 3.0.0 && < 3.0.4.2

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 2.0.9.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3h57-hmj3-gj3p is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

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 HatModerate

Product	Fixed in	Advisory
Red Hat Enterprise Linux 8	`pcs-0:0.10.15-4.el8_8.1`	RHSA-2023:3082
Red Hat Enterprise Linux 8.4 Extended Update Support	`pcs-0:0.10.8-1.el8_4.4`	RHSA-2023:1961
Red Hat Enterprise Linux 8.6 Extended Update Support	`pcs-0:0.10.12-6.el8_6.4`	RHSA-2023:3403
Red Hat Enterprise Linux 9	`pcs-0:0.11.4-7.el9_2`	RHSA-2023:2652
Red Hat Enterprise Linux 9.0 Extended Update Support	`pcs-0:0.11.1-10.el9_0.4`	RHSA-2023:1981
Red Hat Satellite 6.14 for RHEL 8	`rubygem-rack-0:2.2.7-1.el8sat`	RHSA-2023:6818

Frequently Asked Questions

There is a possible DoS vulnerability in the Multipart MIME parsing code in Rack. This vulnerability has been assigned the CVE identifier CVE-2023-27530. Versions Affected: All. Not affected: None Fixed Versions: 3.0.4.2, 2.2.6.3, 2.1.4.3, 2.0.9.3 # Impact The Multipart MIME parsing code in Rack limits the number of file parts, but does not limit the total number of parts that can be uploaded. Carefully crafted requests can abuse this and cause multipart parsing to take longer than expected. All users running an affected release should either upgrade or use one of the workarounds immediatel