CVE-2026-87863

An authenticated HTTPS origin can supply an HSTS `max-age` value that the parser accepts, but time serialization later fails to process. On 64-bit systems, extreme max-age values compute an absolute expiry within standard time integer limits that exceeds calendar time structure bounds. During cache saves, the original HSTS file is truncated before writing a temporary replacement; when serialization fails, the temporary file is deleted, leaving an empty or partial cache. Because the save error is silently ignored during cleanup, curl exits successfully despite the data loss.

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-2026-87863.html
https://curl.se/docs/CVE-2026-87863.json
https://hackerone.com/reports/3972373
https://hackerone.com/reports/3972373

Configurations

No configuration.

History

30 Oct 2026, 12:16

Type	Values Removed	Values Added
CWE		CWE-201
References	~~() https://hackerone.com/reports/3972373 -~~	() https://hackerone.com/reports/3972373 -
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 8.1

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-2026-87863

Mitre link : CVE-2026-87863

CVE.ORG link : CVE-2026-87863

JSON object : View

Products Affected

No product.

CWE

CWE-201

Insertion of Sensitive Information Into Sent Data

{"id": "CVE-2026-87863", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-87863", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-30T12:03:50.833294Z"}}], "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"}, {"status": "affected", "version": "8.10.1", "versionType": "semver", "lessThanOrEqual": "8.10.1"}, {"status": "affected", "version": "8.10.0", "versionType": "semver", "lessThanOrEqual": "8.10.0"}, {"status": "affected", "version": "8.9.1", "versionType": "semver", "lessThanOrEqual": "8.9.1"}, {"status": "affected", "version": "8.9.0", "versionType": "semver", "lessThanOrEqual": "8.9.0"}, {"status": "affected", "version": "8.8.0", "versionType": "semver", "lessThanOrEqual": "8.8.0"}, {"status": "affected", "version": "8.7.1", "versionType": "semver", "lessThanOrEqual": "8.7.1"}, {"status": "affected", "version": "8.7.0", "versionType": "semver", "lessThanOrEqual": "8.7.0"}, {"status": "affected", "version": "8.6.0", "versionType": "semver", "lessThanOrEqual": "8.6.0"}, {"status": "affected", "version": "8.5.0", "versionType": "semver", "lessThanOrEqual": "8.5.0"}, {"status": "affected", "version": "8.4.0", "versionType": "semver", "lessThanOrEqual": "8.4.0"}, {"status": "affected", "version": "8.3.0", "versionType": "semver", "lessThanOrEqual": "8.3.0"}, {"status": "affected", "version": "8.2.1", "versionType": "semver", "lessThanOrEqual": "8.2.1"}, {"status": "affected", "version": "8.2.0", "versionType": "semver", "lessThanOrEqual": "8.2.0"}], "defaultStatus": "unaffected"}]}], "published": "2026-10-20T21:17:20.380", "references": [{"url": "https://curl.se/docs/CVE-2026-87863.html", "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://curl.se/docs/CVE-2026-87863.json", "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://hackerone.com/reports/3972373", "source": "2499f714-1537-4658-8207-48ae4bb9eae9"}, {"url": "https://hackerone.com/reports/3972373", "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": "An authenticated HTTPS origin can supply an HSTS `max-age` value that the\nparser accepts, but time serialization later fails to process. On 64-bit\nsystems, extreme max-age values compute an absolute expiry within standard\ntime integer limits that exceeds calendar time structure bounds. During cache\nsaves, the original HSTS file is truncated before writing a temporary\nreplacement; when serialization fails, the temporary file is deleted, leaving\nan empty or partial cache. Because the save error is silently ignored during\ncleanup, curl exits successfully despite the data loss."}], "lastModified": "2026-10-30T12:16:45.957", "sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9"}