CVE-2026-87862

Importing a `includeSubDomains` parent HSTS entry before a longer-lived child entry, silently drops the child. Consequently, when the parent expires, the child's valid HSTS policy is lost, causing curl to issue unencrypted HTTP requests rather than upgrading to HTTPS.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://curl.se/docs/CVE-2026-87862.html
https://curl.se/docs/CVE-2026-87862.json
https://hackerone.com/reports/3972357
https://hackerone.com/reports/3972357

Configurations

No configuration.

History

30 Oct 2026, 12:16

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 8.1
References	~~() https://hackerone.com/reports/3972357 -~~	() https://hackerone.com/reports/3972357 -
CWE		CWE-201

20 Oct 2026, 21:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-20 21:17

Updated : 2026-10-30 12:16

NVD link : CVE-2026-87862

Mitre link : CVE-2026-87862

CVE.ORG link : CVE-2026-87862

JSON object : View

Products Affected

No product.

CWE

CWE-201

Insertion of Sensitive Information Into Sent Data

{"id": "CVE-2026-87862", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-87862", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-30T11:57:38.044240Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.2}]}, "affected": [{"source": "2499f714-1537-4658-8207-48ae4bb9eae9", "affectedData": [{"vendor": "curl", "product": "curl", "versions": [{"status": "affected", "version": "8.22.0", "versionType": "semver", "lessThanOrEqual": "8.22.0"}, {"status": "affected", "version": "8.21.0", "versionType": "semver", "lessThanOrEqual": "8.21.0"}, {"status": "affected", "version": "8.20.0", "versionType": "semver", "lessThanOrEqual": "8.20.0"}, {"status": "affected", "version": "8.19.0", "versionType": "semver", "lessThanOrEqual": "8.19.0"}, {"status": "affected", "version": "8.18.0", "versionType": "semver", "lessThanOrEqual": "8.18.0"}, {"status": "affected", "version": "8.17.0", "versionType": "semver", "lessThanOrEqual": "8.17.0"}, {"status": "affected", "version": "8.16.0", "versionType": "semver", "lessThanOrEqual": "8.16.0"}, {"status": "affected", "version": "8.15.0", "versionType": "semver", "lessThanOrEqual": "8.15.0"}, {"status": "affected", "version": "8.14.1", "versionType": "semver", "lessThanOrEqual": "8.14.1"}, {"status": "affected", "version": "8.14.0", "versionType": "semver", "lessThanOrEqual": "8.14.0"}, {"status": "affected", "version": "8.13.0", "versionType": "semver", "lessThanOrEqual": "8.13.0"}, {"status": "affected", "version": "8.12.1", "versionType": "semver", "lessThanOrEqual": "8.12.1"}, {"status": "affected", "version": "8.12.0", "versionType": "semver", "lessThanOrEqual": "8.12.0"}, {"status": "affected", "version": "8.11.1", "versionType": "semver", "lessThanOrEqual": "8.11.1"}, {"status": "affected", "version": "8.11.0", "versionType": "semver", "lessThanOrEqual": "8.11.0"}], "defaultStatus": "unaffected"}]}], "published": "2026-10-20T21:17:20.270", "references": [{"url": "https://curl.se/docs/CVE-2026-87862.html", "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://curl.se/docs/CVE-2026-87862.json", "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://hackerone.com/reports/3972357", "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://hackerone.com/reports/3972357", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-201"}]}], "descriptions": [{"lang": "en", "value": "Importing a `includeSubDomains` parent HSTS entry before a longer-lived child\nentry, silently drops the child. Consequently, when the parent expires, the\nchild's valid HSTS policy is lost, causing curl to issue unencrypted HTTP\nrequests rather than upgrading to HTTPS."}], "lastModified": "2026-10-30T12:16:45.787", "sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9"}