CVE-2026-9547
Medium
Elevated severity or exploit probability.
CVSS base
7.4
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS — probability of exploitation (30 days)
0.3%
25.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-297
Published 2026-07-03 · modified 2026-09-15
CVSS breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
| Attack Vector | N | Network |
| Attack Complexity | H | High |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | N | None |
Timeline
- 2026-07-03 — Published (NVD)
- 2026-09-15 — Last modified (NVD)
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.