CVE-2026-87862: HSTS cache import drops longer-lived child

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.3%

EPSS score, percentile 24.3 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

Not scored

The CVE record carries no CVSS score.

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• 8.22.0 through 8.22.0
• 8.21.0 through 8.21.0
• 8.20.0 through 8.20.0
• 8.19.0 through 8.19.0
• 8.18.0 through 8.18.0
• 8.17.0 through 8.17.0

and 6 more in the table below

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: unaffected.

And 3 more version entries in the CVE record.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

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.

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-87862 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 20 Oct 2026.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 24.3), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

HSTS cache import drops longer-lived child

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.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline