Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2023-27536
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 07:47 UTC · Revision 1
Source evidence
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.
osv:CVE-2023-27536
Complete source record
{
"id": "50eb2edc7d17832266ae60f934f2734ed547918a8348fc9efa47f766b0eabacf",
"url": "https://osv.dev/vulnerability/CVE-2023-27536",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2023-27536",
"summary": "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.",
"evidence": "osv:CVE-2023-27536",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2023-27536",
"aliases": [
"CURL-CVE-2023-27536",
"CVE-2023-27536"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/curl/curl",
"type": "GIT",
"events": [
{
"introduced": "64c613c27abb58503eb8a966bee1489562060da0"
},
{
"last_affected": "046209e561b7e9b5aab1aef7daebf29ee6e6e8c7"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "7.22.0"
},
{
"last_affected": "7.88.1"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"curl-7_88_1",
"curl-7_88_0",
"curl-7_87_0",
"curl-7_86_0",
"curl-7_85_0",
"curl-7_84_0",
"curl-7_83_1",
"curl-7_83_0",
"curl-7_82_0",
"curl-7_81_0",
"curl-7_80_0",
"curl-7_79_1",
"curl-7_79_0",
"curl-7_78_0",
"curl-7_77_0",
"curl-7_76_1",
"curl-7_76_0",
"curl-7_75_0",
"curl-7_74_0",
"curl-7_73_0",
"curl-7_72_0",
"curl-7_71_1",
"curl-7_71_0",
"curl-7_70_0",
"curl-7_69_1",
"curl-7_69_0",
"curl-7_68_0",
"curl-7_67_0",
"curl-7_66_0",
"curl-7_65_3",
"curl-7_65_2",
"curl-7_65_1",
"curl-7_65_0",
"curl-7_64_1",
"curl-7_64_0",
"curl-7_63_0",
"curl-7_62_0",
"curl-7_61_1",
"curl-7_61_0",
"curl-7_60_0",
"curl-7_59_0",
"curl-7_58_0",
"curl-7_57_0",
"curl-7_56_1",
"curl-7_56_0",
"curl-7_55_1",
"curl-7_55_0",
"curl-7_54_1",
"curl-7_54_0",
"curl-7_53_1",
"curl-7_53_0",
"curl-7_52_1",
"curl-7_52_0",
"curl-7_51_0",
"curl-7_50_3",
"curl-7_50_2",
"curl-7_50_1",
"curl-7_50_0",
"curl-7_49_1",
"curl-7_49_0",
"curl-7_48_0",
"curl-7_47_1",
"curl-7_47_0",
"curl-7_46_0",
"curl-7_45_0",
"curl-7_44_0",
"curl-7_43_0",
"curl-7_42_0",
"curl-7_41_0",
"curl-7_40_0",
"curl-7_39_0",
"curl-7_38_0",
"curl-7_37_1",
"curl-7_37_0",
"curl-7_36_0",
"curl-7_35_0",
"curl-7_34_0",
"curl-7_33_0",
"curl-7_32_0",
"curl-7_31_0",
"curl-7_30_0",
"curl-7_29_0",
"curl-7_28_1",
"curl-7_28_0",
"curl-7_27_0",
"curl-7_26_0",
"curl-7_25_0",
"curl-7_23_1",
"curl-7_23_0",
"curl-7_22_0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-27536.json"
}
}
],
"modified": "2026-10-28T02:30:26.853042154Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-398330.html",
"https://cert-portal.siemens.com/productcert/html/ssa-806742.html",
"https://cert-portal.siemens.com/productcert/html/ssa-943925.html",
"https://hackerone.com/reports/1895135",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/27xxx/CVE-2023-27536.json",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/",
"https://nvd.nist.gov/vuln/detail/CVE-2023-27536",
"https://security.gentoo.org/glsa/202310-12",
"https://security.netapp.com/advisory/ntap-20230420-0010/",
"https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html"
],
"provider_metadata": {
"cwe_ids": [
"CWE-305"
],
"cna_assigner": "hackerone",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"fixed": "8.0.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "VersionTextExtraction"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/27xxx/CVE-2023-27536.json"
}
},
"related_cves": [
{
"value": "CVE-2023-27536",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 493526,
"published_at": "2023-03-30T00:00:00+00:00"
}