Python-Multipart has Arbitrary File Write via Non-Default Configuration (CVE-2026-24486)
Published Last modified Sources: Red Hat, OSV, CVE.org, BSI
What is affected, what to do
A flaw was found in Python-Multipart, a tool for parsing multipart form data in Python applications. This vulnerability, known as path traversal, allows a remote attacker to write uploaded files to any location on the server's file system.
Update Kludex Python-multipart to version 0.0.22.
- Affected
- Kludex Python-multipart
lt *..0.0.22
- Kludex Python-multipart
- Fixed in
- Kludex Python-multipart
0.0.22
- Kludex Python-multipart
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Metrics
8.6
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
8.6
CVSS v3
Severity High on the scale from 0 to 10.
Source: Red Hat, OSV, CVE.org, BSI
2.2 %
EPSS score
Moderate — model estimates 1-10% exploitation likelihood.
Source: FIRST EPSS, percentile 82.6
Show all metrics
- Severity
- High
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 111.28 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 8.6 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 8.6
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 2.2 %
- Moderate — model estimates 1-10% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 82.6
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · not automatable · Technical impact: partial
- Source: CISA Vulnrichment, as of 27 January 2026
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-22
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
A flaw was found in Python-Multipart, a tool for parsing multipart form data in Python applications. This vulnerability, known as path traversal, allows a remote attacker to write uploaded files to any location on the server's file system. This exploitation occurs when specific non-default configuration options, `UPLOAD_DIR` and `UPLOAD_KEEP_FILENAME=True`, are enabled, and a malicious filename is provided during a file upload. The primary consequence is unauthorized file creation or modification, which could lead to system compromise.
Source: redhat_csaf, OSV (Open Source Vulnerabilities), NVD (NIST), CVE.org (MITRE), cvelistv5, BSI WID Portal, BSI CSAF
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Kludex | python-multipart |
|
|
| fastapiexpert | python-multipart |
|
|
| IBM | Concert |
|
|
| pypi | python-multipart |
|
|
Vendors and products
Weakness classes (CWE)
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Base
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Entry at MITRE CWE-22
References & sources
- github.comKludex/python-multipart/security/advisories/GHSA-wp53-j4wj-2cfgweb, x_refsource_CONFIRM
- NVD (NIST)vuln/detail/CVE-2026-24486advisory
- github.comKludex/python-multipart/commit/9433f4bbc9652bdde82bbe380984e32f…web, x_refsource_MISC
- github.comKludex/python-multipartpackage
- github.comKludex/python-multipart/releases/tag/0.0.22web, x_refsource_MISC
- access.redhat.comsecurity/cve/CVE-2026-24486Vulnerability database, x_refsource_REDHAT
- bugzilla.redhat.comRHBZ#2433132Issue tracking, x_refsource_REDHAT
- security.access.redhat.comdata/csaf/v2/vex/2026/cve-2026-24486.jsonx_sadp-csaf-vex
- access.redhat.comerrata/RHSA-2026:3461Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:3462Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:3960Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:10184Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:42644Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:3782Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:19712Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:3713Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:44696Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:1504Vendor advisory, x_refsource_REDHAT
- access.redhat.comerrata/RHSA-2026:51357Vendor advisory, x_refsource_REDHAT
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedRed Hat ADP
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —https://access.redhat.com/errata/RHSA-2026:44696Affected versions (publisher) changed Red Hat AI Inference Server 3.2, Red Hat AI Inference Server 3.2, Red Hat Ansible Automation Platform 2.6 (+62)Red Hat AI Inference Server 3.2, Red Hat AI Inference Server 3.2, Red Hat Ansible Automation Platform 2.6 (+62)Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Record modifiedRed Hat ADP
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —https://access.redhat.com/errata/RHSA-2026:42644Affected versions (publisher) changed Red Hat AI Inference Server 3.2, Red Hat AI Inference Server 3.2, Red Hat Ansible Automation Platform 2.6 (+62)Red Hat AI Inference Server 3.2, Red Hat AI Inference Server 3.2, Red Hat Ansible Automation Platform 2.6 (+62)Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-24486"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-24486.svg?lang=en" alt="CVE-2026-24486 – NEOSEC Intel" height="20"></a>