# CVE-2026-120572 — Mozilla Firefox

> As of 2026-11-06, CVE-2026-120572 is a HIGH-severity vulnerability in Mozilla Firefox, CVSS v3.1 8.8, EPSS 0.3% (26.1th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-120572, most recently “Firefox for Windows Layout Out-of-Bounds Vulnerability (CVE-2026-120572) Fixed in 159.0.1”.

**Last updated:** 2026-11-03

## What is CVE-2026-120572?

Incorrect boundary conditions in the Layout: Block and Inline component. This vulnerability was fixed in Firefox 159.0.1.

The record classifies CVE-2026-120572 under weakness class [CWE-119](https://intel.threadlinqs.com/cwe/CWE-119). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 4 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 8.8 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 26.1% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-11-03

## Is CVE-2026-120572 being exploited?

It currently carries a trending score of 41 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Mozilla](https://intel.threadlinqs.com/vendors/mozilla): Firefox

## How to fix CVE-2026-120572

No vendor patch reference has been recorded for CVE-2026-120572 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-120572

1 tracked threat in the Threadlinqs corpus references CVE-2026-120572, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Firefox for Windows Layout Out-of-Bounds Vulnerability (CVE-2026-120572) Fixed in 159.0.1](https://intel.threadlinqs.com/threat/TL-2026-5443) — HIGH · 2026-11-06

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-11-07. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [bugzilla.mozilla.org](https://bugzilla.mozilla.org/show_bug.cgi?id=2079035)
- [mozilla.org](https://www.mozilla.org/security/advisories/mfsa2026-123/)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-120572
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