Skip to navigation Skip to main content

Utilities

  • Subscriptions
  • Downloads
  • Red Hat Console
  • Get Support
Red Hat Customer Portal
  • Subscriptions
  • Downloads
  • Red Hat Console
  • Get Support
  • Products

    Top Products

    • Red Hat Enterprise Linux
    • Red Hat OpenShift
    • Red Hat Ansible Automation Platform
    All Products

    Downloads and Containers

    • Downloads
    • Packages
    • Containers

    Top Resources

    • Documentation
    • Product Life Cycles
    • Product Compliance
    • Errata
  • Knowledge

    Red Hat Knowledge Center

    • Knowledgebase Solutions
    • Knowledgebase Articles
    • Customer Portal Labs
    • Errata

    Top Product Docs

    • Red Hat Enterprise Linux
    • Red Hat OpenShift
    • Red Hat Ansible Automation Platform
    All Product Docs

    Training and Certification

    • About
    • Course Index
    • Certification Index
    • Skill Assessment
  • Security

    Red Hat Product Security Center

    • Security Updates
    • Security Advisories
    • Red Hat CVE Database
    • Errata

    References

    • Security Bulletins
    • Security Measurement
    • Severity Ratings
    • Security Data

    Top Resources

    • Security Labs
    • Backporting Policies
    • Security Blog
  • Support

    Red Hat Support

    • Support Cases
    • Troubleshoot
    • Get Support
    • Contact Red Hat Support

    Red Hat Community Support

    • Customer Portal Community
    • Community Discussions
    • Red Hat Accelerator Program

    Top Resources

    • Product Life Cycles
    • Customer Portal Labs
    • Red Hat JBoss Supported Configurations
    • Red Hat Insights
Or troubleshoot an issue.

Select Your Language

  • English
  • Français
  • 한국어
  • 日本語
  • 中文 (中国)

Infrastructure and Management

  • Red Hat Enterprise Linux
  • Red Hat Satellite
  • Red Hat Subscription Management
  • Red Hat Insights
  • Red Hat Ansible Automation Platform

Cloud Computing

  • Red Hat OpenShift
  • Red Hat OpenStack Platform
  • Red Hat OpenShift
  • Red Hat OpenShift AI
  • Red Hat OpenShift Dedicated
  • Red Hat Advanced Cluster Security for Kubernetes
  • Red Hat Advanced Cluster Management for Kubernetes
  • Red Hat Quay
  • Red Hat OpenShift Dev Spaces
  • Red Hat OpenShift Service on AWS

Storage

  • Red Hat Gluster Storage
  • Red Hat Hyperconverged Infrastructure
  • Red Hat Ceph Storage
  • Red Hat OpenShift Data Foundation

Runtimes

  • Red Hat Runtimes
  • Red Hat JBoss Enterprise Application Platform
  • Red Hat Data Grid
  • Red Hat JBoss Web Server
  • Red Hat build of Keycloak
  • Red Hat support for Spring Boot
  • Red Hat build of Node.js
  • Red Hat build of Quarkus

Integration and Automation

  • Red Hat Application Foundations
  • Red Hat Fuse
  • Red Hat AMQ
  • Red Hat 3scale API Management
All Products
Red Hat Product Errata RHSA-2020:5257 - Security Advisory
Issued:
2020-11-30
Updated:
2020-11-30

RHSA-2020:5257 - Security Advisory

  • Overview
  • Updated Packages

Synopsis

Important: firefox security update

Type/Severity

Security Advisory: Important

Red Hat Insights patch analysis

Identify and remediate systems affected by this advisory.

View affected systems

Topic

An update for firefox is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.

This update upgrades Firefox to version 78.5.0 ESR.

Security Fix(es):

  • Mozilla: Parsing mismatches could confuse and bypass security sanitizer for chrome privileged code (CVE-2020-26951)
  • Mozilla: Memory safety bugs fixed in Firefox 83 and Firefox ESR 78.5 (CVE-2020-26968)
  • Mozilla: Variable time processing of cross-origin images during drawImage calls (CVE-2020-16012)
  • Mozilla: Fullscreen could be enabled without displaying the security UI (CVE-2020-26953)
  • Mozilla: XSS through paste (manual and clipboard API) (CVE-2020-26956)
  • Mozilla: Requests intercepted through ServiceWorkers lacked MIME type restrictions (CVE-2020-26958)
  • Mozilla: Use-after-free in WebRequestService (CVE-2020-26959)
  • Mozilla: Potential use-after-free in uses of nsTArray (CVE-2020-26960)
  • Mozilla: DoH did not filter IPv4 mapped IP Addresses (CVE-2020-26961)
  • Mozilla: Software keyboards may have remembered typed passwords (CVE-2020-26965)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, Firefox must be restarted for the changes to take effect.

Affected Products

  • Red Hat Enterprise Linux Server 6 x86_64
  • Red Hat Enterprise Linux Server 6 i386
  • Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
  • Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
  • Red Hat Enterprise Linux Workstation 6 x86_64
  • Red Hat Enterprise Linux Workstation 6 i386
  • Red Hat Enterprise Linux Desktop 6 x86_64
  • Red Hat Enterprise Linux Desktop 6 i386
  • Red Hat Enterprise Linux for IBM z Systems 6 s390x
  • Red Hat Enterprise Linux for Power, big endian 6 ppc64
  • Red Hat Enterprise Linux for Scientific Computing 6 x86_64
  • Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
  • Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
  • Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
  • Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

  • BZ - 1898731 - CVE-2020-26951 Mozilla: Parsing mismatches could confuse and bypass security sanitizer for chrome privileged code
  • BZ - 1898732 - CVE-2020-16012 Mozilla: Variable time processing of cross-origin images during drawImage calls
  • BZ - 1898733 - CVE-2020-26953 Mozilla: Fullscreen could be enabled without displaying the security UI
  • BZ - 1898734 - CVE-2020-26956 Mozilla: XSS through paste (manual and clipboard API)
  • BZ - 1898735 - CVE-2020-26958 Mozilla: Requests intercepted through ServiceWorkers lacked MIME type restrictions
  • BZ - 1898736 - CVE-2020-26959 Mozilla: Use-after-free in WebRequestService
  • BZ - 1898737 - CVE-2020-26960 Mozilla: Potential use-after-free in uses of nsTArray
  • BZ - 1898738 - CVE-2020-26961 Mozilla: DoH did not filter IPv4 mapped IP Addresses
  • BZ - 1898739 - CVE-2020-26965 Mozilla: Software keyboards may have remembered typed passwords
  • BZ - 1898741 - CVE-2020-26968 Mozilla: Memory safety bugs fixed in Firefox 83 and Firefox ESR 78.5

CVEs

  • CVE-2020-16012
  • CVE-2020-26951
  • CVE-2020-26953
  • CVE-2020-26956
  • CVE-2020-26958
  • CVE-2020-26959
  • CVE-2020-26960
  • CVE-2020-26961
  • CVE-2020-26965
  • CVE-2020-26968

References

  • https://access.redhat.com/security/updates/classification/#important
Note: More recent versions of these packages may be available. Click a package name for more details.

Red Hat Enterprise Linux Server 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
x86_64
firefox-78.5.0-1.el6_10.x86_64.rpm SHA-256: b23b9e529e015138d93d495ce555cb2ee7f4d4bd6facb231e3732eabe2ac0b34
firefox-78.5.0-1.el6_10.x86_64.rpm SHA-256: b23b9e529e015138d93d495ce555cb2ee7f4d4bd6facb231e3732eabe2ac0b34
firefox-debuginfo-78.5.0-1.el6_10.x86_64.rpm SHA-256: 924b6c64db4781622b915f7a7c4f67d84188b066971abf4dd01b4078941f2b75
firefox-debuginfo-78.5.0-1.el6_10.x86_64.rpm SHA-256: 924b6c64db4781622b915f7a7c4f67d84188b066971abf4dd01b4078941f2b75
i386
firefox-78.5.0-1.el6_10.i686.rpm SHA-256: 1551c184ebeccb212fa447c2b50e919006351500cceca81b9a47a73e8419f8a3

Red Hat Enterprise Linux Server - Extended Life Cycle Support 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
x86_64
firefox-78.5.0-1.el6_10.x86_64.rpm SHA-256: b23b9e529e015138d93d495ce555cb2ee7f4d4bd6facb231e3732eabe2ac0b34
firefox-debuginfo-78.5.0-1.el6_10.x86_64.rpm SHA-256: 924b6c64db4781622b915f7a7c4f67d84188b066971abf4dd01b4078941f2b75
i386
firefox-78.5.0-1.el6_10.i686.rpm SHA-256: 1551c184ebeccb212fa447c2b50e919006351500cceca81b9a47a73e8419f8a3

Red Hat Enterprise Linux Workstation 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
x86_64
firefox-78.5.0-1.el6_10.x86_64.rpm SHA-256: b23b9e529e015138d93d495ce555cb2ee7f4d4bd6facb231e3732eabe2ac0b34
firefox-debuginfo-78.5.0-1.el6_10.x86_64.rpm SHA-256: 924b6c64db4781622b915f7a7c4f67d84188b066971abf4dd01b4078941f2b75
i386
firefox-78.5.0-1.el6_10.i686.rpm SHA-256: 1551c184ebeccb212fa447c2b50e919006351500cceca81b9a47a73e8419f8a3

Red Hat Enterprise Linux Desktop 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
x86_64
firefox-78.5.0-1.el6_10.x86_64.rpm SHA-256: b23b9e529e015138d93d495ce555cb2ee7f4d4bd6facb231e3732eabe2ac0b34
firefox-debuginfo-78.5.0-1.el6_10.x86_64.rpm SHA-256: 924b6c64db4781622b915f7a7c4f67d84188b066971abf4dd01b4078941f2b75
i386
firefox-78.5.0-1.el6_10.i686.rpm SHA-256: 1551c184ebeccb212fa447c2b50e919006351500cceca81b9a47a73e8419f8a3

Red Hat Enterprise Linux for IBM z Systems 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
s390x
firefox-78.5.0-1.el6_10.s390x.rpm SHA-256: a81999a5d85f405e286c74bad075ecd35c8ad23b191831c8af4653870a755517
firefox-debuginfo-78.5.0-1.el6_10.s390x.rpm SHA-256: 98a59974a2657b6bf60ac3d5ec888a6bd1456ade3c86bfe5207f2d04682211ad

Red Hat Enterprise Linux for Power, big endian 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
ppc64
firefox-78.5.0-1.el6_10.ppc64.rpm SHA-256: 535a7721285706b9286e05ab1fc265f30c95462c04d07cbbf1a0a2ad35f599cd
firefox-debuginfo-78.5.0-1.el6_10.ppc64.rpm SHA-256: 58313f1a013e774126e47387a450daba6df5239e44c3441b1e619e8430212007

Red Hat Enterprise Linux for Scientific Computing 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
x86_64
firefox-78.5.0-1.el6_10.x86_64.rpm SHA-256: b23b9e529e015138d93d495ce555cb2ee7f4d4bd6facb231e3732eabe2ac0b34
firefox-debuginfo-78.5.0-1.el6_10.x86_64.rpm SHA-256: 924b6c64db4781622b915f7a7c4f67d84188b066971abf4dd01b4078941f2b75

Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
s390x
firefox-78.5.0-1.el6_10.s390x.rpm SHA-256: a81999a5d85f405e286c74bad075ecd35c8ad23b191831c8af4653870a755517
firefox-debuginfo-78.5.0-1.el6_10.s390x.rpm SHA-256: 98a59974a2657b6bf60ac3d5ec888a6bd1456ade3c86bfe5207f2d04682211ad

Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
x86_64
firefox-78.5.0-1.el6_10.x86_64.rpm SHA-256: b23b9e529e015138d93d495ce555cb2ee7f4d4bd6facb231e3732eabe2ac0b34
firefox-debuginfo-78.5.0-1.el6_10.x86_64.rpm SHA-256: 924b6c64db4781622b915f7a7c4f67d84188b066971abf4dd01b4078941f2b75
i386
firefox-78.5.0-1.el6_10.i686.rpm SHA-256: 1551c184ebeccb212fa447c2b50e919006351500cceca81b9a47a73e8419f8a3

Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6

SRPM
firefox-78.5.0-1.el6_10.src.rpm SHA-256: 7b603dfa2adaab76f1ad43f563229a50190321df96ad9b65171663893d33ff54
s390x
firefox-78.5.0-1.el6_10.s390x.rpm SHA-256: a81999a5d85f405e286c74bad075ecd35c8ad23b191831c8af4653870a755517
firefox-debuginfo-78.5.0-1.el6_10.s390x.rpm SHA-256: 98a59974a2657b6bf60ac3d5ec888a6bd1456ade3c86bfe5207f2d04682211ad

The Red Hat security contact is secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.

Red Hat LinkedIn YouTube Facebook X, formerly Twitter

Quick Links

  • Downloads
  • Subscriptions
  • Support Cases
  • Customer Service
  • Product Documentation

Help

  • Contact Us
  • Customer Portal FAQ
  • Log-in Assistance

Site Info

  • Trust Red Hat
  • Browser Support Policy
  • Accessibility
  • Awards and Recognition
  • Colophon

Related Sites

  • redhat.com
  • developers.redhat.com
  • connect.redhat.com
  • cloud.redhat.com

Red Hat legal and privacy links

  • About Red Hat
  • Jobs
  • Events
  • Locations
  • Contact Red Hat
  • Red Hat Blog
  • Inclusion at Red Hat
  • Cool Stuff Store
  • Red Hat Summit
© 2025 Red Hat, Inc.

Red Hat legal and privacy links

  • Privacy statement
  • Terms of use
  • All policies and guidelines
  • Digital accessibility