CVE-2026-6879

What it is

`Element.findall()` and fully-consumed `Element.iterfind()` exhibit `O(n^2)` time complexity when using XPath index predicates (e.g. `[1]`, `[last()]`, `[last()-N]`) on XML documents with many same-tag siblings. `Element.find()` is only affected when the first match is near the end  of the sibling list, such as with `[last()]` or `[last()-N]`;  `.//item[1]` short-circuits after the first match.

At a glance

Exploitability

Can be exploited over the network with an admin-level account, but needs a user to act. Limited direct impact.

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. 2026-07-28 15:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-24 13:10 UTC Last updatedMost recent change to the record

Details

Published

2026-07-28 15:17 UTC

Last modified

2026-10-24 13:10 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-407

Record status

Awaiting Analysis

Attack profile CVSS 4.0 · 2.0

Attack vector

Network

Complexity

High

Attack requirements

Present

Privileges needed

High

User interaction

Passive

Confidentiality

None

Integrity

None

Availability

Low