What is CVE-2026-26961?

CVE-2026-26961 is a low-severity vulnerability in Rack, classified under CWE-436. CVSS score: 3.7/10. Published 2026-04-02.

How severe is CVE-2026-26961?

Low severity. CVSS v3 base score is 3.7 out of 10.

Vulnerability in Rack

CVE-2026-26961

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Multipart::Parser extracts the boundary parameter from multipart/form-data using a greedy regular expression. When a Content-Type header contai…

EPSS: 0.000 (2.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Rack — versions < 2.2.23, >= 3.0.0.beta1, < 3.1.21, >= 3.2.0, < 3.2.6

Weakness classification (CWE)

CWE-436

References

https://github.com/rack/rack/security/advisories/GHSA-vgpv-f759-9wx3 (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-26961?: CVE-2026-26961 is a low-severity vulnerability in Rack, classified under CWE-436. CVSS score: 3.7/10. Published 2026-04-02.
How severe is CVE-2026-26961?: Low severity. CVSS v3 base score is 3.7 out of 10.