Upstream information

CVE-2026-26961 at MITRE

Description

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Multipart::Parser extracts the boundary parameter from multipart/form-data using a greedy regular expression. When a Content-Type header contains multiple boundary parameters, Rack selects the last one rather than the first. In deployments where an upstream proxy, WAF, or intermediary interprets the first boundary parameter, this mismatch can allow an attacker to smuggle multipart content past upstream inspection and have Rack parse a different body structure than the intermediary validated. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having moderate severity.

CVSS v3 Scores
CVSS detail CNA (GitHub) SUSE
Base Score 3.7 3.7
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack Vector Network Network
Attack Complexity High High
Privileges Required None None
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact None None
Integrity Impact Low Low
Availability Impact None None
CVSSv3 Version 3.1 3.1
CVSS v4 Scores
CVSS detail SUSE
Base Score 6.3
Vector CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Attack Vector Network
Attack Complexity High
Attack Requirements None
Privileges Required None
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact Low
Vulnerable System Availability Impact None
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0
SUSE Bugzilla entry: 1261391 [NEW]

No SUSE Security Announcements cross referenced.


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise High Availability Extension 15 SP7 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP7 rubygem-rack Affected
SUSE Linux Enterprise High Availability Extension 16.1 hawk2 Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 rmt-server Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP7 rmt-server Affected
SUSE Linux Enterprise Module for Server Applications 15 SP7 rmt-server Affected
SUSE Linux Enterprise Server 15 SP7 rmt-server Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 rmt-server Affected
SUSE Linux Enterprise Server for SAP applications 16.1 hawk2 Affected
openSUSE Leap 15.6 hawk2 Not affected
openSUSE Leap 15.6 rmt-server Affected
openSUSE Leap 15.6 rubygem-rack Affected
openSUSE Leap 15.6 rubygem-rack-1_6 Affected
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Availability Extension 12 SP5 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP4 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP4 rubygem-rack Affected
SUSE Linux Enterprise High Availability Extension 15 SP5 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP5 rubygem-rack Affected
SUSE Linux Enterprise High Performance Computing 15 SP4 rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP5 rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS rmt-server Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP4 rmt-server Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP5 rmt-server Affected
SUSE Linux Enterprise Module for Server Applications 15 SP4 rmt-server Affected
SUSE Linux Enterprise Module for Server Applications 15 SP5 rmt-server Affected
SUSE Linux Enterprise Module for Server Applications 15 SP6 rmt-server Affected
SUSE Linux Enterprise Server 15 SP4 rmt-server Affected
SUSE Linux Enterprise Server 15 SP4-LTSS rmt-server Affected
SUSE Linux Enterprise Server 15 SP5 rmt-server Affected
SUSE Linux Enterprise Server 15 SP5-LTSS rmt-server Affected
SUSE Linux Enterprise Server 15 SP6 rmt-server Affected
SUSE Linux Enterprise Server 15 SP6-LTSS rmt-server Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP5 hawk2 Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 rmt-server Affected
SUSE Manager Proxy 4.3 rmt-server Affected
SUSE Manager Proxy LTS 4.3 rmt-server Affected
SUSE Manager Retail Branch Server 4.3 rmt-server Affected
SUSE Manager Retail Branch Server LTS 4.3 rmt-server Affected
SUSE Manager Server 4.3 rmt-server Affected
SUSE Manager Server LTS 4.3 rmt-server Affected
Products past their end of life and not receiving proactive updates anymore.
SUSE CaaS Platform 4.0 rmt-server Affected
SUSE Enterprise Storage 6 rmt-server Affected
SUSE Enterprise Storage 7 rmt-server Affected
SUSE Enterprise Storage 7.1 rmt-server Affected
SUSE Linux Enterprise High Availability Extension 12 SP4 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 rubygem-rack Affected
SUSE Linux Enterprise High Availability Extension 15 SP1 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP1 rubygem-rack Affected
SUSE Linux Enterprise High Availability Extension 15 SP2 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP2 rubygem-rack Affected
SUSE Linux Enterprise High Availability Extension 15 SP3 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP3 rubygem-rack Affected
SUSE Linux Enterprise High Availability Extension 15 SP6 hawk2 Not affected
SUSE Linux Enterprise High Availability Extension 15 SP6 rubygem-rack Affected
SUSE Linux Enterprise High Performance Computing 15 SP1 rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP3 rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS rmt-server Affected
SUSE Linux Enterprise High Performance Computing 15 SP6 rmt-server Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP1 rmt-server Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP2 rmt-server Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP3 rmt-server Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP6 rmt-server Affected
SUSE Linux Enterprise Module for Server Applications 15 SP1 rmt-server Affected
SUSE Linux Enterprise Module for Server Applications 15 SP2 rmt-server Affected
SUSE Linux Enterprise Module for Server Applications 15 SP3 rmt-server Affected
SUSE Linux Enterprise Real Time 15 SP2 rmt-server Affected
SUSE Linux Enterprise Real Time 15 SP3 rmt-server Affected
SUSE Linux Enterprise Real Time 15 SP4 rmt-server Affected
SUSE Linux Enterprise Server 15 SP1 rmt-server Affected
SUSE Linux Enterprise Server 15 SP1-BCL rmt-server Affected
SUSE Linux Enterprise Server 15 SP1-LTSS rmt-server Affected
SUSE Linux Enterprise Server 15 SP2 rmt-server Affected
SUSE Linux Enterprise Server 15 SP2-BCL rmt-server Affected
SUSE Linux Enterprise Server 15 SP2-LTSS rmt-server Affected
SUSE Linux Enterprise Server 15 SP3 rmt-server Affected
SUSE Linux Enterprise Server 15 SP3-BCL rmt-server Affected
SUSE Linux Enterprise Server 15 SP3-LTSS rmt-server Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1 rmt-server Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 rmt-server Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 rmt-server Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 rmt-server Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 rmt-server Affected
SUSE Manager Proxy 4.0 rmt-server Affected
SUSE Manager Proxy 4.1 rmt-server Affected
SUSE Manager Proxy 4.2 rmt-server Affected
SUSE Manager Retail Branch Server 4.0 rmt-server Affected
SUSE Manager Retail Branch Server 4.1 rmt-server Affected
SUSE Manager Retail Branch Server 4.2 rmt-server Affected
SUSE Manager Server 4.0 rmt-server Affected
SUSE Manager Server 4.1 rmt-server Affected
SUSE Manager Server 4.2 rmt-server Affected
openSUSE Leap 15.3 hawk2 Not affected
openSUSE Leap 15.3 rmt-server Affected
openSUSE Leap 15.3 rubygem-rack Affected
openSUSE Leap 15.3 rubygem-rack-1_6 Affected
openSUSE Leap 15.4 hawk2 Not affected
openSUSE Leap 15.4 rmt-server Affected
openSUSE Leap 15.4 rubygem-rack Affected
openSUSE Leap 15.4 rubygem-rack-1_6 Affected
openSUSE Leap 15.5 hawk2 Not affected
openSUSE Leap 15.5 rmt-server Affected
openSUSE Leap 15.5 rubygem-rack Affected
openSUSE Leap 15.5 rubygem-rack-1_6 Affected
Container Status
suse/rmt-server rmt-serverAffected


SUSE Timeline for this CVE

CVE page created: Thu Apr 2 20:03:20 2026
CVE page last modified: Fri Apr 3 14:48:32 2026