CVE-2024-39316

MEDIUM

Rack ReDoS Vulnerability in HTTP Accept Headers Parsing

Published July 3, 2024Updated February 4, 2026Source: osv

Summary

### Summary A Regular Expression Denial of Service (ReDoS) vulnerability exists in the `Rack::Request::Helpers` module when parsing HTTP Accept headers. This vulnerability can be exploited by an attacker sending specially crafted `Accept-Encoding` or `Accept-Language` headers, causing the server to spend excessive time processing the request and leading to a Denial of Service (DoS). ### Details The fix for https://github.com/rack/rack/security/advisories/GHSA-54rr-7fvw-6x8f was not applied to the main branch and thus while the issue was fixed for the Rack v3.0 release series, it was not fixed in the v3.1 release series until v3.1.5.

Remediation

Upgrade to the fixed version using your package manager.

Bundler

Update rack to 3.1.5 or later

gem install rack -v 3.1.5

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (1)

Package	Ecosystem	Affected	Fixed In
rack	rubygems	3.1.0, 3.1.1, 3.1.2, 3.1.3 (+1 more)	3.1.5

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CWE-1333
View on MITRE

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 6.5 score means for each attack dimension.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

Frequently Asked Questions

What is CVE-2024-39316?: Rack ReDoS Vulnerability in HTTP Accept Headers Parsing This vulnerability has been assigned a severity rating of MEDIUM (CVSS score: 6.5/10).
How do I check if my project is affected by CVE-2024-39316?: CVE-2024-39316 affects rack. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2024-39316 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score

6.5

Exploitation requires specific conditions or has limited impact. Remediate within weeks.

Also Known As

GHSA-cj83-2ww7-mvq7

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