# RHSA-2020:3557: firefox security update

RHSA-2020:3557, released August 26, 2020, fixes 11 CVEs in firefox (version 0:78.2.0-2.el8_2). None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2020-3557
- Platform: Linux
- Released: Aug 26, 2020
- Priority: High (Closes CVE-2020-12422, high severity)
- CVEs: 11, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2020:3557

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [firefox](https://patchblox.com/security/data/product/linux/firefox.md) | RHEL 8 | 0:78.2.0-2.el8_2 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2020-12422](https://patchblox.com/security/data/cve/CVE-2020-12422.md) | High | Firefox ESR: In non-standard configurations, a JPEG image created by JavaScript could have caused an internal variable… | 8.8 | 0.0194 |  |
| [CVE-2020-12390](https://patchblox.com/security/data/cve/CVE-2020-12390.md) | High | Firefox ESR: Incorrect origin serialization of URLs with IPv6 addresses could lead to incorrect security checks. | 9.8 | 0.0162 |  |
| [CVE-2020-15656](https://patchblox.com/security/data/cve/CVE-2020-15656.md) | High | Firefox ESR and 2 others: JIT optimizations involving the Javascript arguments object could confuse later optimizations. | 8.8 | 0.0152 |  |
| [CVE-2020-15669](https://patchblox.com/security/data/cve/CVE-2020-15669.md) | High | firefox: ELSA-2020-3557: firefox security update (IMPORTANT) | 8.8 | 0.0112 |  |
| [CVE-2020-12424](https://patchblox.com/security/data/cve/CVE-2020-12424.md) | Routine | Firefox ESR: When constructing a permission prompt for WebRTC, a URI was supplied from the content process. | 6.5 | 0.0161 |  |
| [CVE-2020-12425](https://patchblox.com/security/data/cve/CVE-2020-12425.md) | Routine | Firefox ESR: Due to confusion processing a hyphen character in Date.parse(), a one-byte out of bounds read could have… | 6.5 | 0.0157 |  |
| [CVE-2020-15654](https://patchblox.com/security/data/cve/CVE-2020-15654.md) | Routine | Firefox ESR and 2 others: When in an endless loop, a website specifying a custom cursor using CSS could make it look like the user… | 6.5 | 0.0142 |  |
| [CVE-2020-15653](https://patchblox.com/security/data/cve/CVE-2020-15653.md) | Routine | Firefox ESR and 2 others: An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links. | 6.5 | 0.0140 |  |
| [CVE-2020-15664](https://patchblox.com/security/data/cve/CVE-2020-15664.md) | Routine | Firefox ESR and 2 others: By holding a reference to the eval() function from an about:blank window, a malicious webpage could have… | 6.5 | 0.0139 |  |
| [CVE-2020-15658](https://patchblox.com/security/data/cve/CVE-2020-15658.md) | Routine | Firefox ESR and 2 others: The code for downloading files did not properly take care of special characters, which led to an attacker… | 6.5 | 0.0139 |  |
| [CVE-2020-15648](https://patchblox.com/security/data/cve/CVE-2020-15648.md) | Routine | Firefox ESR: Using object or embed tags, it was possible to frame other websites, even if they disallowed framing… | 6.5 | 0.0114 |  |

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Data as of 2026-11-11T13:47:35Z 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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