CVE-2026-87862
Published Oct 20, 2026
Description
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.
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References
Frequently Asked Questions
What is 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.
How do I check if I'm vulnerable to CVE-2026-87862? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.