Summary
Excon does not redact additional sensitive/risky headers when following redirects
Workarounds
Users can backport the fix to a custom redirect follower middleware.
Impact
The redirect follower middleware previously failed to strip a number of headers that are known to be sensitive and did not provide a way to provide a custom list of headers to strip.
What kind of vulnerability is it? Who is impacted?
This could cause inadvertent leakage of sensitive data for users of the RedirectFollower middleware in cases where the initial request includes header information that is not intended for the new target.
CVE-2026-54171 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.5.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Patch exists and is released in v1.5.0
Frequently Asked Questions
- What is CVE-2026-54171? CVE-2026-54171 is a medium-severity security vulnerability in excon (rubygems), affecting versions < 1.5.0. It is fixed in 1.5.0.
- How severe is CVE-2026-54171? CVE-2026-54171 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of excon are affected by CVE-2026-54171? excon (rubygems) versions < 1.5.0 is affected.
- Is there a fix for CVE-2026-54171? Yes. CVE-2026-54171 is fixed in 1.5.0. Upgrade to this version or later.
- Is CVE-2026-54171 exploitable, and should I be worried? Whether CVE-2026-54171 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-54171 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-54171? Upgrade
exconto 1.5.0 or later.