What’s Vulnerable › Vulnerabilities

CVE-2023-34457: MechanicalSoup vulnerable to malicious web server reading arbitrary files on client using file input inside HTML form

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-07-05 · updated 2026-06-17
• Weakness: CWE-20

Description

MechanicalSoup is a Python library for automating interaction with websites. Starting in version 0.2.0 and prior to version 1.3.0, a malicious web server can read arbitrary files on the client using a `<input type="file" ...>` inside HTML form. All users of MechanicalSoup's form submission are affected, unless they took very specific (and manual) steps to reset HTML form field values. Version 1.3.0 contains a patch for this issue.

Affected products

• MechanicalSoup: before 1.3.0 — fixed in 1.3.0

How to fix

Upgrade to a fixed version: MechanicalSoup 1.3.0. Check the vendor advisory for mitigations.

References

• https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e
• https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0
• https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4
• https://security.netapp.com/advisory/ntap-20230803-0005/
• https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e
• https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0
• https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4
• https://security.netapp.com/advisory/ntap-20230803-0005/

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