{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-87861", "assignerOrgId": "2499f714-1537-4658-8207-48ae4bb9eae9", "state": "PUBLISHED", "assignerShortName": "curl", "dateReserved": "2026-09-09T13:17:34.696Z", "datePublished": "2026-10-20T20:09:28.592Z", "dateUpdated": "2026-10-20T20:09:28.592Z"}, "containers": {"cna": {"title": "cross-origin reuse of a Negotiate connection", "descriptions": [{"lang": "en", "value": "When using ambient user credentials, an HTTP request directed to one origin\nmay be dispatched over a connection previously authenticated via Negotiate for\na different origin, leaving the request's intended credentials unused."}], "providerMetadata": {"orgId": "2499f714-1537-4658-8207-48ae4bb9eae9", "shortName": "curl", "dateUpdated": "2026-10-20T20:09:28.592Z"}, "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-201 Information Exposure Through Sent Data"}]}], "affected": [{"vendor": "curl", "product": "curl", "versions": [{"version": "8.22.0", "status": "affected", "lessThanOrEqual": "8.22.0", "versionType": "semver"}, {"version": "8.21.0", "status": "affected", "lessThanOrEqual": "8.21.0", "versionType": "semver"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://curl.se/docs/CVE-2026-87861.json", "name": "json"}, {"url": "https://curl.se/docs/CVE-2026-87861.html", "name": "www"}, {"url": "https://hackerone.com/reports/3972094", "name": "issue"}], "credits": [{"lang": "en", "value": "Axel Mierczuk", "type": "finder"}, {"lang": "en", "value": "Stefan Eissing", "type": "remediation developer"}]}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "curl", "vendor": "curl", "versions": [{"lessThanOrEqual": "8.22.0", "status": "affected", "version": "8.22.0", "versionType": "semver"}, {"lessThanOrEqual": "8.21.0", "status": "affected", "version": "8.21.0", "versionType": "semver"}]}], "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "When using ambient user credentials, an HTTP request directed to one origin\nmay be dispatched over a connection previously authenticated via Negotiate for\na different origin, leaving the request's intended credentials unused."}], "id": "CVE-2026-87861", "lastModified": "2026-10-20T21:17:20.167", "metrics": {}, "published": "2026-10-20T21:17:20.167", "references": [{"source": "2499f714-1537-4658-8207-48ae4bb9eae9", "url": "https://curl.se/docs/CVE-2026-87861.html"}, {"source": "2499f714-1537-4658-8207-48ae4bb9eae9", "url": "https://curl.se/docs/CVE-2026-87861.json"}, {"source": "2499f714-1537-4658-8207-48ae4bb9eae9", "url": "https://hackerone.com/reports/3972094"}], "sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9", "vulnStatus": "Received"}

{"acknowledgement": "Red Hat would like to thank Axel Mierczuk for reporting this issue.", "bugzilla": {"description": "curl: curl: cross-origin reuse of a Negotiate connection", "id": "2550611", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2550611"}, "csaw": false, "cvss3": {"cvss3_base_score": "3.7", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N", "status": "draft"}, "cwe": "CWE-201", "details": ["A flaw was found in curl. When ambient user credentials\u2014where authentication is handled implicitly without providing a username\u2014are used, curl may improperly reuse an existing connection authenticated via Negotiate for a different server origin. This improper connection reuse can cause requests intended for one server to be transmitted over an established connection to another, potentially resulting in information disclosure."], "name": "CVE-2026-87861", "package_state": [{"cpe": "cpe:/a:redhat:confidential_compute_attestation:1", "fix_state": "Not affected", "package_name": "build-of-trustee/trustee-rhel9", "product_name": "Confidential Compute Attestation"}, {"cpe": "cpe:/a:redhat:confidential_compute_attestation:1", "fix_state": "Not affected", "package_name": "openshift-sandboxed-containers/osc-podvm-payload-rhel9", "product_name": "Confidential Compute Attestation"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "curl", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "igvm", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "rust", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "s390utils", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "snphost", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "trustee", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "curl", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "curl", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "curl", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "curl", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "rust", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "snphost", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "curl", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "rust", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:jboss_core_services:1", "fix_state": "Not affected", "package_name": "jbcs-httpd24-curl", "product_name": "Red Hat JBoss Core Services"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Not affected", "package_name": "foreman", "product_name": "Red Hat Satellite 6"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Not affected", "package_name": "openvox-agent", "product_name": "Red Hat Satellite 6"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Not affected", "package_name": "puppet-agent", "product_name": "Red Hat Satellite 6"}], "public_date": "2026-10-14T12:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-87861\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-87861"], "statement": "Red Hat Product Security rates this vulnerability as Low impact because exploitation requires specific preconditions involving Negotiate authentication with ambient credentials, and successful exploitation only results in limited information exposure without compromising system integrity or availability. In typical Red Hat environments, applications rarely multiplex requests across different origins while relying on blank user identities for Kerberos or SPNEGO authentication. As a result, standard enterprise deployments face minimal exposure unless custom software explicitly employs this credential handling pattern.", "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 80.0, "confidence_source": "inferred", "scores": [{"score": 80.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "product": "curl", "vendor": "curl"}], "created": "2026-10-17T02:00:07.713070+00:00", "updated": "2026-10-20T22:30:18.059442+00:00", "vendors": ["curl", "curl$PRODUCT$curl"]}