libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers. (CVE-2026-5773)
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.
libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers. (CVE-2026-5773)
Description
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 v3.1
Score 7.5high
Affected software
pkg:deb/ubuntu/curl?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/curl?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/curl?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/curl?arch=source&distro=jammypkg:deb/ubuntu/curl?arch=source&distro=noblepkg:deb/ubuntu/curl?arch=source&distro=questingpkg:deb/ubuntu/curl?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-5773
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
Patch Information
Threat ID: 6ab4be70f7a7c54106f0d452
Added to database: 09/24/2026, 06:08:48 UTC
Last updated: 09/24/2026, 07:18:15 UTC
Views: 3
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.