# CVE-2022-28284: Mozilla Firefox ESR and 2 others: Improper Encoding or Escaping of Output

CVE-2022-28284 is fixed in 5 products on 2 platforms, first by Mozilla Firefox (en-US) 99.0, released April 5, 2022. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2022-28284
- Priority: High
- CVSS: 8.8 (Medium)
- EPSS: 0.0059
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 6, 2022
- Weakness: CWE-116: Improper Encoding or Escaping of Output
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2022-28284

## Description

SVG's <code>&lt;use&gt;</code> element could have been used to load unexpected content that could have executed script in certain circumstances. While the specification seems to allow this, other browsers do not, and web developers relied on this property for script security so gecko's implementation was aligned with theirs. This vulnerability affects Firefox < 99.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | Mozilla Firefox (en-US) | 99.0 | [Mozilla Firefox (en-US) 99.0](https://patchblox.com/security/data/fix/windows-app/mozilla.firefox-99.0.md) | Apr 5, 2022 |
| Windows apps | Mozilla Firefox ESR (en-US) | 102.0 | [Mozilla Firefox ESR (en-US) 102.0](https://patchblox.com/security/data/fix/windows-app/mozilla.firefox.esr-102.0.md) | Jun 23, 2022 |
| Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 99.0+build2-0ubuntu0.18.04.2 | [firefox 99.0+build2-0ubuntu0.18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-99.0-build2-0ubuntu0.18.04.2.md) | Apr 6, 2022 |
| Linux | firefox Ubuntu 20.04 LTS (focal) | 99.0+build2-0ubuntu0.20.04.2 | [firefox 99.0+build2-0ubuntu0.20.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-99.0-build2-0ubuntu0.20.04.2.md) | Apr 6, 2022 |
| Linux | firefox Ubuntu 22.04.1 LTS (jammy) | 1:1snap1-0ubuntu1 | [firefox 1:1snap1-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-firefox-1-1snap1-0ubuntu1.md) | Apr 6, 2022 |
| Linux | firefox-geckodriver Ubuntu 18.04.6 LTS (bionic) | 99.0+build2-0ubuntu0.18.04.2 | [firefox-geckodriver 99.0+build2-0ubuntu0.18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-geckodriver-99.0-build2-0ubuntu0.18.04.2.md) | Apr 6, 2022 |
| Linux | firefox-geckodriver Ubuntu 20.04 LTS (focal) | 99.0+build2-0ubuntu0.20.04.2 | [firefox-geckodriver 99.0+build2-0ubuntu0.20.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-geckodriver-99.0-build2-0ubuntu0.20.04.2.md) | Apr 6, 2022 |
| Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 99.0+build2-0ubuntu0.18.04.2 | [firefox-mozsymbols 99.0+build2-0ubuntu0.18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-99.0-build2-0ubuntu0.18.04.2.md) | Apr 6, 2022 |
| Linux | firefox-mozsymbols Ubuntu 20.04 LTS (focal) | 99.0+build2-0ubuntu0.20.04.2 | [firefox-mozsymbols 99.0+build2-0ubuntu0.20.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-mozsymbols-99.0-build2-0ubuntu0.20.04.2.md) | Apr 6, 2022 |

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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

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