Ruby rack: Prior to 2.2.25, 3.1.23, and 3.2.8, Rack::Multipart::Parser can retain parsed data in its internal
Affects ruby-rackSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 2.2.25 : patch ruby-rack soon.
Data as of 13 Nov 2026, 22:37 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.5 |
|---|
- Patch
- Available – fixed in 2.2.25
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10ruby-rackpkg:deb/ubuntu/ruby-rack?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSruby-rackpkg:deb/ubuntu/ruby-rack?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSruby-rackpkg:deb/ubuntu/ruby-rack?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSruby-rackpkg:deb/ubuntu/ruby-rack?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSruby-rackpkg:deb/ubuntu/ruby-rack?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSruby-rackpkg:deb/ubuntu/ruby-rack?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Ruby Rack to version 2.2.25, 3.1.23, or 3.2.8 or later where this issue is fixed. No other mitigations are specified or required.
Description
A vulnerability in Ruby Rack prior to versions 2.2.25, 3.1.23, and 3.2.8 allows the Rack::Multipart::Parser to retain parsed data in its internal buffer improperly. This can be exploited by an unauthenticated attacker sending a specially crafted multipart request to cause the buffer to grow uncontrollably, leading to memory exhaustion of the worker process. The issue affects applications that parse multipart requests and is fixed in the specified versions.
References
- ubuntu.com/security/CVE-2026-125111 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-125111 (opens in a new tab)
- github.com/rack/rack/security/advisories/GHSA-5v64-555j-wjxm (opens in a new tab)
- github.com/rack/rack/commit/244e75a840cee0823f86d5d01dc374505a8abed8 (opens in a new tab)
- github.com/rack/rack/commit/2eaa5b1026a03a43b6537b1a0b233707ba887702 (opens in a new tab)
- github.com/rack/rack/commit/c9b4698595050838342bd3b5a0fc9ab908065f8f (opens in a new tab)