A flaw was found in curl. When libcurl is built with the libssh2 backend and uses a hashed known-hosts file, host key verification can mistakenly report a key mismatch as a missing key to custom verification callbacks. A remote attacker who intercepts or controls the Secure Shell (SSH) connection can exploit this flaw to make a previously pinned server appear as a new host. As a result, the application may inadvertently authenticate to an untrusted server, leading to credential exposure and the receipt of malicious data.
Metrics
Affected Vendors & Products
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Advisories
| Source | ID | Title |
|---|---|---|
 Ubuntu USN |
USN-8927-1 | curl vulnerabilities |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sat, 17 Oct 2026 00:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A flaw was found in curl. When libcurl is built with the libssh2 backend and uses a hashed known-hosts file, host key verification can mistakenly report a key mismatch as a missing key to custom verification callbacks. A remote attacker who intercepts or controls the Secure Shell (SSH) connection can exploit this flaw to make a previously pinned server appear as a new host. As a result, the application may inadvertently authenticate to an untrusted server, leading to credential exposure and the receipt of malicious data. | |
| Title | curl: curl: knownhost callback mismatches key as missing | |
| Weaknesses | CWE-295 | |
| References |
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| Metrics |
threat_severity
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cvssV3_1
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Projects
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MITRE
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Vulnrichment
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NVD
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Redhat
OpenCVE Enrichment
Updated: 2026-10-17T02:15:14Z
Weaknesses