Server-Side Request Forgery (SSRF) Affecting curl package, versions <8.18.0-1ubuntu2.1


Severity

Recommended
low

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.03% (9th percentile)

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  • Snyk IDSNYK-UBUNTU2604-CURL-16335424
  • published4 May 2026
  • disclosed13 May 2026

Introduced: 4 May 2026

NewCVE-2026-5773  (opens in a new tab)
CWE-918  (opens in a new tab)

How to fix?

Upgrade Ubuntu:26.04 curl to version 8.18.0-1ubuntu2.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream curl package and not the curl package as distributed by Ubuntu. See How to fix? for Ubuntu:26.04 relevant fixed versions and status.

libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers.

libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.

When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network transfer operation that was requested by an application could wrongfully reuse an existing SMB connection to the same server that was using a different 'share' than the new subsequent transfer should.

This could in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place. When this happens, the same credentials are used and the server name is the same.

CVSS Base Scores

version 3.1