What is CVE-2026-54171?

CVE-2026-54171 is a medium-severity vulnerability in Excon, classified under Insertion of Sensitive Information into Sent Data. CVSS score: 6.5/10. Published 2026-07-17.

How severe is CVE-2026-54171?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Excon

CVE-2026-54171

Excon is usable, fast, simple HTTP 1.1 for Ruby. Prior to 1.5.0, Excon's RedirectFollower middleware failed to strip additional sensitive headers when following redirects and did not provide a custom list of headers to strip. This could cause inadvertent leakage of sensitive data when the initial request includes header information that is not intended for the new target. This issue is fixed in version 1.5.0.

Published 2026-07-17 · last modified 2026-07-29.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (35.4th percentile), scored 2026-10-16.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Excon — versions < 1.5.0
Excon Project

Weakness classification (CWE)

CWE-201 — Insertion of Sensitive Information into Sent Data

References

github.com/excon/excon/commit/ea89a35308a12f4b791b6c50f2cbd33f94889fa3 (Patch)
github.com/excon/excon/pull/901 (Patch, Issue Tracking)
github.com/excon/excon/security/advisories/GHSA-48rx-c7pg-q66r (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-54171?: CVE-2026-54171 is a medium-severity vulnerability in Excon, classified under Insertion of Sensitive Information into Sent Data. CVSS score: 6.5/10. Published 2026-07-17.
How severe is CVE-2026-54171?: Medium severity. CVSS v3 base score is 6.5 out of 10.