GHSA-jr4f-4564-w3mr
A vulnerability in libcurl causes proxy authentication credentials to leak when reusing a libcurl handle for sequential transfers with environment-variable proxy configuration. Specifically, if the first transfer authenticates to one proxy using Digest authentication, the subsequent transfer to a different proxy may incorrectly send the previous proxy's Proxy-Authorization header.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-8927) occurs in libcurl when a single handle is reused for multiple sequential transfers that use different proxies configured via environment variables. The proxy authentication state is not cleared between requests, causing the Proxy-Authorization header from the first proxy to be sent to a different proxy in a later request. This can lead to unintended credential leakage between proxies.
Potential Impact
The impact is the unintended disclosure of proxy authentication credentials to a proxy server that should not receive them. This could potentially expose sensitive authentication information to unauthorized proxies, increasing the risk of credential compromise or misuse.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should avoid reusing libcurl handles for sequential transfers involving different proxies configured via environment variables or explicitly clear proxy authentication state between requests if possible.
GHSA-jr4f-4564-w3mr
Description
A vulnerability in libcurl causes proxy authentication credentials to leak when reusing a libcurl handle for sequential transfers with environment-variable proxy configuration. Specifically, if the first transfer authenticates to one proxy using Digest authentication, the subsequent transfer to a different proxy may incorrectly send the previous proxy's Proxy-Authorization header.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-8927) occurs in libcurl when a single handle is reused for multiple sequential transfers that use different proxies configured via environment variables. The proxy authentication state is not cleared between requests, causing the Proxy-Authorization header from the first proxy to be sent to a different proxy in a later request. This can lead to unintended credential leakage between proxies.
Potential Impact
The impact is the unintended disclosure of proxy authentication credentials to a proxy server that should not receive them. This could potentially expose sensitive authentication information to unauthorized proxies, increasing the risk of credential compromise or misuse.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should avoid reusing libcurl handles for sequential transfers involving different proxies configured via environment variables or explicitly clear proxy authentication state between requests if possible.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-jr4f-4564-w3mr
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-8927"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a483cb427e9c79719d81f5f
Added to database: 07/03/2026, 22:50:28 UTC
Last enriched: 07/03/2026, 23:02:44 UTC
Last updated: 07/04/2026, 00:11:25 UTC
Views: 2
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