---
id: "CVE-2026-117979"
kind: "vulnerability"
aliases: ["CVE-2026-117979"]
title: "Firefox: WebRender boundary check flaw fixed in recent releases"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browsers", "desktop", "firefox", "runtime"]
not_affected_if: ["fixed-version"]
published_at: "2026-10-27T14:16:55+00:00"
first_seen_at: "2026-10-27T14:32:24+00:00"
updated_at: "2026-10-27T14:35:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117979", "first_seen_at": "2026-10-27T14:32:24+00:00"}]
---

# Firefox: WebRender boundary check flaw fixed in recent releases

Incorrect boundary conditions in Firefox's WebRender graphics component were fixed in Firefox 159 and ESR 115.44 and 153.6. The sources do not say what an attacker can do with it.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `firefox --version` or check Help > About Firefox and compare with `159` or the ESR builds `115.44` and `153.6`
- unknown

## Fix

- Update Firefox to `159` or later
- Update Firefox ESR to `115.44` or `153.6`, whichever branch is in use

## Timeline

- 2026-10-27T14:32:24+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117979

## From the sources

Incorrect boundary conditions in the Graphics: WebRender component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.

---

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