CVE-2026-54171 Excon: redact additional sensitive/risky headers when following redirects
Excon library leaks sensitive headers to redirect targets, allowing attackers to read confidential data if redirects are followed.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-54171?
CVE-2026-54171 is a medium-severity vulnerability in excon, published on 17 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-201
Which versions are affected by CVE-2026-54171?
2 open source packages ship an affected version, including excon. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
excon RubyGems | All versions | 1.5.0 |
excon RubyGems | All versions | 1.5.0 |
Products include Excon Project Excon.
How do I fix CVE-2026-54171?
Upgrade excon to 1.5.0 or later.
Is CVE-2026-54171 being exploited?
There is no known exploitation of CVE-2026-54171 in the wild and no public exploit code.
Sources
Also known as AZL-92460, CLEANSTART-2026-JH87007, DEBIAN-CVE-2026-54171, GHSA-48rx-c7pg-q66r, MINI-467w-h5vp-cr2f, MINI-95w8-cgrm-rw46 and 3 more.