---
id: "CVE-2026-117999"
kind: "vulnerability"
aliases: ["CVE-2026-117999"]
title: "Firefox: race condition in IPC component may allow unspecified exploitation"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browsers", "desktop", "firefox", "runtime"]
not_affected_if: ["firefox-159-or-later", "firefox-esr-153.6-or-later"]
published_at: "2026-10-27T14:16:57+00:00"
first_seen_at: "2026-10-27T14:32:25+00:00"
updated_at: "2026-10-27T14:34:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117999", "first_seen_at": "2026-10-27T14:32:25+00:00"}]
---

# Firefox: race condition in IPC component may allow unspecified exploitation

A race condition in Firefox's inter-process communication (IPC) component was fixed in Firefox 159 and Firefox ESR 153.6. The sources do not state what an attacker gains from it.

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

## How to check

- Check the Firefox version with `about:support` or the Help menu; unknown whether earlier versions are exposed beyond what is listed here.

## Fix

- Update Firefox to `159` or later.
- Update Firefox ESR to `153.6` or later.

## Timeline

- 2026-10-27T14:32:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117999

## From the sources

Race condition in the IPC component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_