Improper Verification of Cryptographic Signature Affecting curl package, versions <0:8.21.0-5.amzn2023.0.1


Severity

Recommended
medium

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.33% (24th percentile)

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  • Snyk IDSNYK-AMZN2023-CURL-19816444
  • published15 Sept 2026
  • disclosed3 Jul 2026

Introduced: 3 Jul 2026

CVE-2026-9547  (opens in a new tab)
CWE-347  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 curl to version 0:8.21.0-5.amzn2023.0.1 or higher.
This issue was patched in ALAS2023-2026-2132.

NVD Description

Note: Versions mentioned in the description apply only to the upstream curl package and not the curl package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1