MediumFix available
curl — security advisory
An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.
- Products
- curl
- Affected versions
- Not specified
- Fixed versions
- 7.88.1-r1, 8.0.0-r0, 8.0.1-r0
- CVEs
- CVE-2023-27535
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 14:56 UTC · Revision 1
Source evidence
An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.
osv:ALPINE-CVE-2023-27535
curl
Fixed versions: 8.0.1-r0
curl
Fixed versions: 8.0.1-r0
curl
Fixed versions: 8.0.1-r0
curl
Fixed versions: 7.88.1-r1
curl
Fixed versions: 8.0.0-r0
curl
Fixed versions: 8.0.0-r0
curl
Fixed versions: 8.0.0-r0
curl
Fixed versions: 8.0.0-r0
curl
Fixed versions: 8.0.0-r0
curl
Fixed versions: 8.0.0-r0
curl
Fixed versions: 8.0.0-r0
Complete source record
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"modified": "2026-10-26T17:17:58.615919844Z",
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