Vulnerability in Shopify Pitchfork

CVE-2025-30221

Pitchfork is a preforking HTTP server for Rack applications. Versions prior to 0.11.0 are vulnerable to HTTP Response Header Injection when used in conjunction with Rack 3. The issue was fixed in Pitchfork release 0.11.0. No known workarounds are available.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (18.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 18.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-30221: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-30221?
CVE-2025-30221 is a medium-severity vulnerability in Shopify Pitchfork, classified under HTTP Response Splitting. CVSS score: 4.3/10. Published 2025-03-27.
How severe is CVE-2025-30221?
Medium severity. CVSS v3 base score is 4.3 out of 10.