# CVE-2020-12394: Firefox ESR: A logic flaw in our location bar implementation could have allowed a local attacker to spoof the current…

CVE-2020-12394 is fixed in 4 products on 2 platforms, first by firefox 76.0+build2-0ubuntu0.18.04.1, released May 6, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2020-12394
- Priority: Routine
- CVSS: 3.3 (Medium)
- EPSS: 0.0029
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 6, 2020
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2020-12394

## Description

A logic flaw in our location bar implementation could have allowed a local attacker to spoof the current location by selecting a different origin and removing focus from the input element. This vulnerability affects Firefox < 76.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | Mozilla Firefox ESR (en-US) | 78.0esr | [Mozilla Firefox ESR (en-US) 78.0esr](https://patchblox.com/security/data/fix/windows-app/mozilla.firefox.esr-78.0esr.md) | Jun 25, 2020 |
| Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 76.0+build2-0ubuntu0.18.04.1 | [firefox 76.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-76.0-build2-0ubuntu0.18.04.1.md) | May 6, 2020 |
| Linux | firefox Ubuntu 20.04 LTS (focal) | 76.0+build2-0ubuntu0.20.04.1 | [firefox 76.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-76.0-build2-0ubuntu0.20.04.1.md) | May 6, 2020 |
| Linux | firefox-geckodriver Ubuntu 18.04.6 LTS (bionic) | 76.0+build2-0ubuntu0.18.04.1 | [firefox-geckodriver 76.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-geckodriver-76.0-build2-0ubuntu0.18.04.1.md) | May 6, 2020 |
| Linux | firefox-geckodriver Ubuntu 20.04 LTS (focal) | 76.0+build2-0ubuntu0.20.04.1 | [firefox-geckodriver 76.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-geckodriver-76.0-build2-0ubuntu0.20.04.1.md) | May 6, 2020 |
| Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 76.0+build2-0ubuntu0.18.04.1 | [firefox-mozsymbols 76.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-76.0-build2-0ubuntu0.18.04.1.md) | May 6, 2020 |
| Linux | firefox-mozsymbols Ubuntu 20.04 LTS (focal) | 76.0+build2-0ubuntu0.20.04.1 | [firefox-mozsymbols 76.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-mozsymbols-76.0-build2-0ubuntu0.20.04.1.md) | May 6, 2020 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.