CVE-2026-97151

What it is

mammoth (aka mammoth.js) before 1.12.2 is vulnerable to prototype pollution when reading the styles defined in a document. Converting a crafted .docx file allows an attacker to add arbitrary properties to Object.prototype. In 1.11.0 through 1.12.1, applications that convert further documents in the same process and return the converted HTML can also disclose the contents of local server files (to the party supplying the documents) by setting externalFileAccess to true.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-24 04:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-24 21:04 UTC Last updatedMost recent change to the record

Details

Published

2026-09-24 04:18 UTC

Last modified

2026-09-24 21:04 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-1321 · Prototype pollution

Record status

Awaiting Analysis

Attack profile CVSS 4.0 · 8.4

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

Low

Availability

High