Sensitive-header disclosure via incomplete redirect redaction
Published Jul 17, 2026 · Updated Jul 17, 2026
Sensitive-header exposure in excon before 1.5.0 allows remote attackers to read request secrets through a crafted HTTP redirect. RedirectFollower duplicates the original header map for the redirected request but removes only Authorization, Proxy-Connection, Proxy-Authorization, and Host, leaving cookies and token headers attached. Exploitation requires an application to use RedirectFollower, send a sensitive unlisted header, and follow a redirect to an attacker-controlled target; the consequence is disclosure of that header value.
Summary
What happened
Sensitive-header exposure in excon before 1.5.0 allows remote attackers to read request secrets through a crafted HTTP redirect. RedirectFollower duplicates the original header map for the redirected request but removes only Authorization, Proxy-Connection, Proxy-Authorization, and Host, leaving cookies and token headers attached. Exploitation requires an application to use RedirectFollower, send a sensitive unlisted header, and follow a redirect to an attacker-controlled target; the consequence is disclosure of that header value.
The record
- CVE
- CVE-2026-54171
- Published
- Jul 17, 2026
- Updated
- Jul 17, 2026
- Vendor
- excon
- Product
- excon
- Classifications
- CWE-201, T1539
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 17, 2026CVE publishedPublication date reported by the CVE source.
- Jul 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 1.5.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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