---
title: "CVE-2026-92055: Mozilla Firefox - Privilege Escalation"
description: "Mozilla Firefox < 156 and Firefox ESR < 153.3 contain a privilege escalation caused by a flaw in the DevTools component, letting attackers escalate privileges, exploit requires no special conditions."
url: https://panop.io/threat-heartbeat/CVE-2026-92055/
---

# CVE-2026-92055 Mozilla Firefox - Privilege Escalation

Mozilla Firefox < 156 and Firefox ESR < 153.3 contain a privilege escalation caused by a flaw in the DevTools component, letting attackers escalate privileges, exploit requires no special conditions.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.23% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-92055)

## Details

Type

Privilege Escalation

Impact

Privilege Escalation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Published

15 September 2026

Updated

15 October 2026

Weakness

[CWE-269](https://cwe.mitre.org/data/definitions/269.html)

## Vendor fix

Update to Firefox 156 or Firefox ESR 153.3 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-92055](https://nvd.nist.gov/vuln/detail/CVE-2026-92055)
- [https://www.mozilla.org/security/advisories/mfsa2026-93/](https://www.mozilla.org/security/advisories/mfsa2026-93/)
- [https://www.mozilla.org/security/advisories/mfsa2026-94/](https://www.mozilla.org/security/advisories/mfsa2026-94/)
- [https://www.mozilla.org/security/advisories/mfsa2026-96/](https://www.mozilla.org/security/advisories/mfsa2026-96/)
- [https://bugzilla.mozilla.org/show\_bug.cgi?id=2063652](https://bugzilla.mozilla.org/show_bug.cgi?id=2063652)
- [https://www.mozilla.org/security/advisories/mfsa2026-90/](https://www.mozilla.org/security/advisories/mfsa2026-90/)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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