CVE-2026-9547
SSH improper host validation
CVSS Score
7.4
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-297 |
| Vendor | curl |
| Product | curl |
| Published | Jul 3, 2026 |
| Last Updated | Sep 15, 2026 |
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Affected Versions
curl / curl
7.69.0 < 8.14.2 8.15.0 < 8.16.1 8.17.0 < 8.20.1
curl / curl
507cf6a13db0375eadd4655b4c64710db29e9cf2 < 0b8dbbc63c98777e4584cb9fbd71df3464008ad1
curl / curl
8.20.0 8.19.0 8.18.0 8.17.0 8.16.0 8.15.0 8.14.1 8.14.0 8.13.0 8.12.1 8.12.0 8.11.1 8.11.0 8.10.1 8.10.0 8.9.1 8.9.0 8.8.0 8.7.1 8.7.0 8.6.0 8.5.0 8.4.0 8.3.0 8.2.1 8.2.0 8.1.2 8.1.1 8.1.0 8.0.1 8.0.0 7.88.1 7.88.0 7.87.0 7.86.0 7.85.0 7.84.0 7.83.1 7.83.0 7.82.0 7.81.0 7.80.0 7.79.1 7.79.0 7.78.0 7.77.0 7.76.1 7.76.0 7.75.0 7.74.0 7.73.0 7.72.0 7.71.1 7.71.0 7.70.0 7.69.1 7.69.0
References
Credits
Joshua Rogers (Aisle Research) Joshua Rogers (Aisle Research)