Upstream information
Description
Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, `Rack::Multipart::Parser` buffers the entire multipart preamble (bytes before the first boundary) in memory without any size limit. A client can send a large preamble followed by a valid boundary, causing significant memory use and potential process termination due to out-of-memory (OOM) conditions. Remote attackers can trigger large transient memory spikes by including a long preamble in multipart/form-data requests. The impact scales with allowed request sizes and concurrency, potentially causing worker crashes or severe slowdown due to garbage collection. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a preamble size limit (e.g., 16 KiB) or discard preamble data entirely. Workarounds include limiting total request body size at the proxy or web server level and monitoring memory and set per-process limits to prevent OOM conditions.SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having important severity.
| CVSS detail | CNA (GitHub) | SUSE |
|---|---|---|
| Base Score | 7.5 | 7.5 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network | Network |
| Attack Complexity | Low | Low |
| Privileges Required | None | None |
| User Interaction | None | None |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | None | None |
| Integrity Impact | None | None |
| Availability Impact | High | High |
| CVSSv3 Version | 3.1 | 3.1 |
| CVSS detail | SUSE |
|---|---|
| Base Score | 8.7 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| Attack Vector | Network |
| Attack Complexity | Low |
| Attack Requirements | None |
| Privileges Required | None |
| User Interaction | None |
| Vulnerable System Confidentiality Impact | None |
| Vulnerable System Integrity Impact | None |
| Vulnerable System Availability Impact | High |
| Subsequent System Confidentiality Impact | None |
| Subsequent System Integrity Impact | None |
| Subsequent System Availability Impact | None |
| CVSSv4 Version | 4.0 |
List of released packages
| Product(s) | Fixed package version(s) | References |
|---|---|---|
| openSUSE Tumbleweed |
| Patchnames: openSUSE-Tumbleweed-2025-15621 |
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Please note that this evaluation state might be work in progress, incomplete or outdated.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 SP6 | rubygem-rack | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | rubygem-rack | Affected |
| openSUSE Leap 15.6 | rubygem-rack | Affected |
| openSUSE Leap 15.6 | rubygem-rack-1_6 | Not affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Availability Extension 15 SP3 | rubygem-rack | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP4 | rubygem-rack | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP5 | rubygem-rack | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE Linux Enterprise High Availability Extension 15 | rubygem-rack | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP1 | rubygem-rack | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP2 | rubygem-rack | Affected |
| openSUSE Leap 15.3 | rubygem-rack | Affected |
| openSUSE Leap 15.3 | rubygem-rack-1_6 | Not affected |
| openSUSE Leap 15.4 | rubygem-rack | Affected |
| openSUSE Leap 15.4 | rubygem-rack-1_6 | Not affected |
| openSUSE Leap 15.5 | rubygem-rack | Affected |
| openSUSE Leap 15.5 | rubygem-rack-1_6 | Not affected |
SUSE Timeline for this CVE
CVE page created: Tue Oct 7 18:02:35 2025CVE page last modified: Fri Oct 10 01:31:56 2025