Vulnerability · Published Oct 20, 2026 · Assigned by curl
CVE-2026-87862HSTS cache import drops longer-lived child
High 8.1
In plain English
A high-severity security flaw in curl from curl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 63% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.1High
Exploit odds (30 days)1.0%top 37.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | curl | 8.23.0-r0 | ALPINE-CVE-2026-87862 |
| Alpine:v3.24 | curl | 8.23.0-r0 | ALPINE-CVE-2026-87862 |
| Debian:13 | curl | no fix listed | DEBIAN-CVE-2026-87862 |
| Debian:14 | curl | no fix listed | DEBIAN-CVE-2026-87862 |
| Ubuntu:22.04:LTS | curl | 7.81.0-1ubuntu1.30 | USN-8932-1 |
| Ubuntu:22.04:LTS | curl | 7.81.0-1ubuntu1.30 | UBUNTU-CVE-2026-87862 |
| Ubuntu:24.04:LTS | curl | 8.5.0-2ubuntu10.16 | UBUNTU-CVE-2026-87862 |
| Ubuntu:24.04:LTS | curl | 8.5.0-2ubuntu10.16 | USN-8932-1 |
| Ubuntu:26.04:LTS | curl | 8.18.0-1ubuntu2.8 | USN-8927-1 |
| Ubuntu:26.04:LTS | curl | 8.18.0-1ubuntu2.8 | UBUNTU-CVE-2026-87862 |
| Ubuntu:26.10 | curl | 8.20.0-2ubuntu11.1 | UBUNTU-CVE-2026-87862 |
| Ubuntu:26.10 | curl | 8.20.0-2ubuntu11.1 | USN-8927-2 |
Affected products (as reported)
Weakness: CWE-201 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H