How severe is CVE-2026-24486?

CVE-2026-24486 has a CVSS score of 8.6/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-24486?

CVE-2026-24486 affects the following packages: python-multipart (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-24486?

Update python-multipart to 0.0.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-24486 is resolved across your whole dependency graph.

How do I detect CVE-2026-24486 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-multipart, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-24486 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-24486 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2026-24486, including 1 documented proof-of-concept exploit on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2026-24486?

CVE-2026-24486 has an EPSS (Exploit Prediction Scoring System) score of 2.2%, placing it in the 83th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-24486?

CVE-2026-24486 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-24486 published, and has it been updated?

CVE-2026-24486 was published on January 27, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

HIGH severity

CVE-2026-24486 — python-multipart

HIGHFix: Kludex/python-multipart@9433f4b

CVE-2026-24486 is a high-severity (CVSS 8.6) Path Traversal vulnerability in python-multipart. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for python-multipart — see the affected versions and patch details below.

Python-Multipart has Arbitrary File Write via Non-Default Configuration

Also known asGHSA-wp53-j4wj-2cfgPYSEC-2026-1852

Published

Jan 27, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-24486.

EPSS Exploitation Probability

via FIRST.org ↗

2.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs83th percentile — riskier than 83% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐍python-multipart

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

A Path Traversal vulnerability exists when using non-default configuration options UPLOAD_DIR and UPLOAD_KEEP_FILENAME=True. An attacker can write uploaded files to arbitrary locations on the filesystem by crafting a malicious filename.

Details

When UPLOAD_DIR is set and UPLOAD_KEEP_FILENAME is True, the library constructs the file path using os.path.join(file_dir, fname). Due to the behavior of os.path.join(), if the filename begins with a /, all preceding path components are discarded:

os.path.join("/upload/dir", "/etc/malicious") == "/etc/malicious"

This allows an attacker to bypass the intended upload directory and write files to arbitrary paths.

Affected Configuration

Projects are only affected if all of the following are true:

UPLOAD_DIR is set
UPLOAD_KEEP_FILENAME is set to True
The uploaded file exceeds MAX_MEMORY_FILE_SIZE (triggering a flush to disk)

The default configuration is not vulnerable.

Impact

Arbitrary file write to attacker-controlled paths on the filesystem.

Mitigation

Upgrade to version 0.0.22, or avoid using UPLOAD_KEEP_FILENAME=True in project configurations.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`python-multipart`	all versions	0.0.22`pip install --upgrade 'python-multipart==0.0.22'`

Affected Products

1 product · 1 configurations

Application

python-multipartfastapiexpert

< 0.0.22

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-52543webappspython

Python-Multipart 0.0.22 - Path Traversal

by jefersoncardoso.dev · Apr 30, 2026

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-multipart, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update python-multipart to 0.0.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-24486 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

Workaround published by Red Hat

To mitigate this vulnerability, avoid enabling the `UPLOAD_KEEP_FILENAME=True` configuration option in applications using `python-multipart`. This option, when used with `UPLOAD_DIR`, allows an attacker to write files to arbitrary locations. Disabling or not configuring `UPLOAD_KEEP_FILENAME=True` prevents the path traversal vulnerability.

Source: Red Hat security advisory for CVE-2026-24486 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat AI Inference Server 3.2	`rhaiis/vllm-cuda-rhel9:1772160593`	RHSA-2026:3461
Red Hat AI Inference Server 3.2	`rhaiis/vllm-rocm-rhel9:1772160625`	RHSA-2026:3462
Red Hat Ansible Automation Platform 2.6	`ansible-automation-platform-26/lightspeed-chatbot-rhel9:1772204398`	RHSA-2026:3960
Red Hat OpenShift AI 2.25	`rhoai/odh-feature-server-rhel9:1776338381`	RHSA-2026:10184
Red Hat OpenShift AI 2.25	`rhoai/odh-vllm-gaudi-rhel9:1772093278`	RHSA-2026:3782
Red Hat OpenShift AI 2.25	`rhoai/odh-vllm-cuda-rhel9:1783998774`	RHSA-2026:42644
Red Hat OpenShift AI 3.3	`rhoai/odh-vllm-cpu-rhel9:1778264363`	RHSA-2026:19712
Red Hat OpenShift AI 3.3	`rhoai/odh-vllm-gaudi-rhel9:1770956034`	RHSA-2026:3713

Frequently Asked Questions

### Summary A Path Traversal vulnerability exists when using non-default configuration options `UPLOAD_DIR` and `UPLOAD_KEEP_FILENAME=True`. An attacker can write uploaded files to arbitrary locations on the filesystem by crafting a malicious filename. ### Details When `UPLOAD_DIR` is set and `UPLOAD_KEEP_FILENAME` is `True`, the library constructs the file path using `os.path.join(file_dir, fname)`. Due to the behavior of `os.path.join()`, if the filename begins with a `/`, all preceding path components are discarded: ```py os.path.join("/upload/dir", "/etc/malicious") == "/etc/malicious"

O3 Security · Impact-Aware SCA

Is CVE-2026-24486 in your dependencies?

Find it across PyPI, including transitive dependencies.

Scan my dependencies How O3 SCA works