A flaw was found in curl. When persistent HTTP Strict Transport Security (HSTS) caching is enabled, a remote HTTPS server can return an out-of-range expiration value that fails time serialization during cache saving. Because curl truncates the cache file prior to writing the update, this serialization failure causes the persistent HSTS cache to be deleted or emptied. As a result, stored security policies for known hosts are lost, potentially allowing future connections to fall back to insecure communication.
Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8927-1 curl vulnerabilities
Ubuntu USN Ubuntu USN USN-8932-1 curl vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 17 Oct 2026 00:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in curl. When persistent HTTP Strict Transport Security (HSTS) caching is enabled, a remote HTTPS server can return an out-of-range expiration value that fails time serialization during cache saving. Because curl truncates the cache file prior to writing the update, this serialization failure causes the persistent HSTS cache to be deleted or emptied. As a result, stored security policies for known hosts are lost, potentially allowing future connections to fall back to insecure communication.
Title curl: curl: Hsts Response Erases Persisted Entries
Weaknesses CWE-201
References
Metrics threat_severity

None

cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'}

threat_severity

Low


Projects

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cve-icon MITRE

No data.

cve-icon Vulnrichment

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cve-icon NVD

No data.

cve-icon Redhat

Severity : Low

Publid Date: 2026-10-14T12:00:00Z

Links: CVE-2026-87863 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-17T02:45:13Z

Weaknesses