CVE-2023-27536

An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in unauthorized access to sensitive information. The safest option is to not reuse connections if the CURLOPT_GSSAPI_DELEGATION option has been changed.

• CWE-305
• CWE-287

• https://hackerone.com/reports/1895135Exploit, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2023/04/msg00025.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/Mailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202310-12Third Party Advisory
• https://security.netapp.com/advisory/ntap-20230420-0010/Third Party Advisory
• https://hackerone.com/reports/1895135Exploit, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2023/04/msg00025.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/Mailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202310-12Third Party Advisory
• https://security.netapp.com/advisory/ntap-20230420-0010/Third Party Advisory

Published

Mar 30, 2023

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2023-27530A DoS vulnerability exists in Rack <v3.0.4.2, <v2.2.6.3, <v2…7.5
• CVE-2023-27531There is a deserialization of untrusted data vulnerability i…5.3
• CVE-2023-27532Vulnerability in Veeam Backup & Replication component allows…7.5
• CVE-2023-27533A vulnerability in input validation exists in curl <8.0 duri…8.8
• CVE-2023-27534A path traversal vulnerability exists in curl <8.0.0 SFTP im…8.8
• CVE-2023-27535An authentication bypass vulnerability exists in libcurl <8.…5.9
• CVE-2023-27537A double free vulnerability exists in libcurl <8.0.0 when sh…5.9
• CVE-2023-27538An authentication bypass vulnerability exists in libcurl pri…5.5
• CVE-2023-27539There is a denial of service vulnerability in the header par…5.3
• CVE-2023-2754The Cloudflare WARP client for Windows assigns loopback IPv4…6.8
• CVE-2023-27540IBM Watson CP4D Data Stores 4.6.0 does not properly allocate…7.5
• CVE-2023-27545IBM Watson CloudPak for Data Data Stores information disclos…5.5