Description
multipart is a fast multipart/form-data parser for python. Prior to 1.2.2, 1.3.1 and 1.4.0-dev, the parse_options_header() function in multipart.py uses a regular expression with an ambiguous alternation, which can cause exponential backtracking (ReDoS) when parsing maliciously crafted HTTP or multipart segment headers. This can be abused for denial of service (DoS) attacks against web applications using this library to parse request headers or multipart/form-data streams. The issue is fixed in 1.2.2, 1.3.1 and 1.4.0-dev.
Metrics
CVSS 3.1 7.5/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| defnull | multipart | >= 1.3.0, < 1.3.1; < 1.2.2 |
| Red Hat | Red Hat AI Inference Server 3.2 | — |
| Red Hat | Red Hat AI Inference Server 3.2 | — |
| Red Hat | Red Hat AI Inference Server 3.2 | — |
| Red Hat | Red Hat OpenShift AI 2.25 | — |
| Red Hat | Red Hat OpenShift AI 2.25 | — |
| Red Hat | Red Hat OpenShift AI 2.25 | — |
| Red Hat | Red Hat OpenShift AI 2.25 | — |
| Red Hat | Red Hat OpenShift AI 2.25 | — |
| Red Hat | Red Hat OpenShift AI 3.3 | — |
| Red Hat | Lightspeed Core | — |
| Red Hat | Lightspeed Core | — |
| Red Hat | OpenShift Lightspeed | — |
| Red Hat | OpenShift Lightspeed | — |
| Red Hat | Red Hat AI Inference Server | — |
| Red Hat | Red Hat AI Inference Server | — |
| Red Hat | Red Hat AI Inference Server | — |
| Red Hat | Red Hat AI Inference Server | — |
| Red Hat | Red Hat Ansible Automation Platform 2 | — |
| Red Hat | Red Hat Ansible Automation Platform 2 | — |
| Red Hat | Red Hat Ansible Automation Platform 2 | — |
| Red Hat | Red Hat Enterprise Linux AI (RHEL AI) 3 | — |
| Red Hat | Red Hat Enterprise Linux AI (RHEL AI) 3 | — |
| Red Hat | Red Hat Enterprise Linux AI (RHEL AI) 3 | — |
| Red Hat | Red Hat Enterprise Linux AI (RHEL AI) 3 | — |
| Red Hat | Red Hat Enterprise Linux AI (RHEL AI) 3 | — |
| Red Hat | Red Hat Enterprise Linux AI (RHEL AI) 3 | — |
| Red Hat | Red Hat Enterprise Linux AI (RHEL AI) 3 | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — |
References
- https://github.com/defnull/multipart/security/advisories/GHSA-p2m9-wcp5-6qw3
- https://access.redhat.com/errata/RHSA-2026:10184
- https://access.redhat.com/errata/RHSA-2026:37275
- https://access.redhat.com/errata/RHSA-2026:42644
- https://access.redhat.com/errata/RHSA-2026:5809
- https://access.redhat.com/errata/RHSA-2026:6761
- https://access.redhat.com/errata/RHSA-2026:6762
- https://access.redhat.com/security/cve/CVE-2026-28356
- https://bugzilla.redhat.com/show_bug.cgi?id=2447059
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28356.json
Timeline
- Published
- Mar 12, 2026
- Last modified
- Aug 24, 2026
- NVD status
- Deferred