Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2025-61921

7.5 · HIGH

Sinatra is a domain-specific language for creating web applications in Ruby.

Published Oct 10, 2025CWE-1333EPSS 0.50%

Overview

CVE-2025-61921 is a high-severity vulnerability. It was published on October 10, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical description

Sinatra is a domain-specific language for creating web applications in Ruby. In versions prior to 4.2.0, there is a denial of service vulnerability in the `If-Match` and `If-None-Match` header parsing component of Sinatra, if the `etag` method is used when constructing the response. Carefully crafted input can cause `If-Match` and `If-None-Match` header parsing in Sinatra to take an unexpected amount of time, possibly resulting in a denial of service attack vector. This header is typically involved in generating the `ETag` header value. Any applications that use the `etag` method when generating a response are impacted. Version 4.2.0 fixes the issue.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refbugs.ruby-lang.org/issues/19104GitHubgithub.com/sinatra/sinatra/issues/2120GitHubgithub.com/sinatra/sinatra/pull/1823GitHubgithub.com/sinatra/sinatra/pull/2121GitHubgithub.com/sinatra/sinatra/security/advisories/GHSA-mr3q-g2mv-mr4q

How CyberStrike helps

Frequently asked questions

What is CVE-2025-61921?

CVE-2025-61921 is a high-severity vulnerability. It was published on October 10, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-61921?

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2025-61921?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2025-61921?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-61921 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related HIGH CVEs from 2025

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999