SSH improper host validation (curl curl)

CVE-2026-9547
HIGH 7.4

At a glance

Source
NVD
EPSS
EPSS 0.36 % · percentile 30 ()
State
PUBLISHED
Published
Updated
Assigner
curl
NVD status
Modified

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.

Weaknesses (CWE)

  • CWE-297 — Improper Validation of Certificate with Host Mismatch

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCISA-ADP
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
curl · curlaffected 7.69.0 < 8.14.2 ; affected 8.15.0 < 8.16.1 ; affected 8.17.0 < 8.20.1
curl · curlaffected 507cf6a13db0375eadd4655b4c64710db29e9cf2 < 0b8dbbc63c98777e4584cb9fbd71df3464008ad1
curl · curlaffected 8.20.0 ; affected 8.19.0 ; affected 8.18.0 ; affected 8.17.0 ; affected 8.16.0 ; affected 8.15.0

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD