CVE-2026-9547
Discovered by AISLEPUBLISHEDCWE-297 Improper Validation of Certificate with Host Mismatch
Description
When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the `known_hosts` file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.
Affected Products
| Vendor | Product | Version | Status |
|---|---|---|---|
| curl | curl | 8.20.0 | affected |
| curl | curl | 8.19.0 | — |
| curl | curl | 8.18.0 | — |
| curl | curl | 8.17.0 | — |
| curl | curl | 8.16.0 | — |
| curl | curl | 8.15.0 | — |
| curl | curl | 8.14.1 | — |
| curl | curl | 8.14.0 | — |
| curl | curl | 8.13.0 | — |
| curl | curl | 8.12.1 | — |
| curl | curl | 8.12.0 | — |
| curl | curl | 8.11.1 | — |
| curl | curl | 8.11.0 | — |
| curl | curl | 8.10.1 | — |
| curl | curl | 8.10.0 | — |
| curl | curl | 8.9.1 | — |
| curl | curl | 8.9.0 | — |
| curl | curl | 8.8.0 | — |
| curl | curl | 8.7.1 | — |
| curl | curl | 8.7.0 | — |
| curl | curl | 8.6.0 | — |
| curl | curl | 8.5.0 | — |
| curl | curl | 8.4.0 | — |
| curl | curl | 8.3.0 | — |
| curl | curl | 8.2.1 | — |
| curl | curl | 8.2.0 | — |
| curl | curl | 8.1.2 | — |
| curl | curl | 8.1.1 | — |
| curl | curl | 8.1.0 | — |
| curl | curl | 8.0.1 | — |
| curl | curl | 8.0.0 | — |
| curl | curl | 7.88.1 | — |
| curl | curl | 7.88.0 | — |
| curl | curl | 7.87.0 | — |
| curl | curl | 7.86.0 | — |
| curl | curl | 7.85.0 | — |
| curl | curl | 7.84.0 | — |
| curl | curl | 7.83.1 | — |
| curl | curl | 7.83.0 | — |
| curl | curl | 7.82.0 | — |
| curl | curl | 7.81.0 | — |
| curl | curl | 7.80.0 | — |
| curl | curl | 7.79.1 | — |
| curl | curl | 7.79.0 | — |
| curl | curl | 7.78.0 | — |
| curl | curl | 7.77.0 | — |
| curl | curl | 7.76.1 | — |
| curl | curl | 7.76.0 | — |
| curl | curl | 7.75.0 | — |
| curl | curl | 7.74.0 | — |
| curl | curl | 7.73.0 | — |
| curl | curl | 7.72.0 | — |
| curl | curl | 7.71.1 | — |
| curl | curl | 7.71.0 | — |
| curl | curl | 7.70.0 | — |
| curl | curl | 7.69.1 | — |
| curl | curl | 7.69.0 | — |
Credits
- Joshua Rogers (Aisle Research)(finder)
- Joshua Rogers (Aisle Research)(remediation developer)