VDB
CVE-2026-86409
CVE-2026-86409
PUBLISHED
CVSS 8.1 HIGH
Reported by curl · Published October 20, 2026
Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication, contrary to expectations and documentation. A subsequent transfer on the same handle still sends an `Authorization: AWS4-HMAC-SHA256` header to whatever URL isset next, leaking state information.
Risk Scores
CVSS 3.1
8.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| curl | curl | 8.21.0, 8.20.0, 8.19.0 |
| alpine | curl | 0 |
| curl | curl | 8.21.0, 8.20.0, 8.19.0 |
Timeline
- CVE Published
- Oct 14, 2026 PoC Published
- Oct 21, 2026 EPSS Score
- Oct 25, 2026 EPSS Score
- Oct 27, 2026 EPSS Score
- Oct 29, 2026 EPSS Score
- Oct 30, 2026 EPSS Score