RHSA-2026:49922: Important: thunderbird security update

Published Aug 4, 2026
·
Updated

Important: thunderbird security update

Other sources

Mozilla Thunderbird is a standalone mail and newsgroup client.Security Fix(es): firefox: thunderbird: Site isolation issue in the DOM: Navigation component (CVE-2026-15719) firefox: thunderbird: Invalid pointer in the JavaScript: WebAssembly component (CVE-2026-15718) firefox: thunderbird: Mitigation bypass in the Enterprise Policies component (CVE-2026-16390) firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: cubeb component (CVE-2026-16350) firefox: thunderbird: Information disclosure in the Storage: IndexedDB component (CVE-2026-16391) firefox: thunderbird: Site isolation issue in the Networking: HTTP component (CVE-2026-16375) firefox: thunderbird: Sandbox escape due to use-after-free in the Disability Access APIs component (CVE-2026-16356) firefox: thunderbird: JIT miscompilation in the JavaScript: WebAssembly component (CVE-2026-16363) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.13 and Firefox 153 (CVE-2026-16412) firefox: thunderbird: Same-origin policy bypass in the Networking: DNS component (CVE-2026-16381) firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-16355) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.38 and Firefox ESR 140.13 (CVE-2026-16361) firefox: thunderbird: Sandbox escape due to use-after-free in the Disability Access APIs component (CVE-2026-16352) firefox: thunderbird: Incorrect boundary conditions in the JavaScript: WebAssembly component (CVE-2026-16368) firefox: thunderbird: Mitigation bypass in the PDF Viewer component (CVE-2026-16377) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.38, Firefox ESR 140.13 and Firefox 153 (CVE-2026-16360) firefox: thunderbird: Use-after-free in the WebRTC: Audio/Video component (CVE-2026-16362) firefox: thunderbird: Site isolation issue in the Graphics: WebRender component (CVE-2026-16358) firefox: thunderbird: Site isolation issue in the Networking component (CVE-2026-16387) firefox: thunderbird: Same-origin policy bypass in the DOM: Navigation component (CVE-2026-16349) firefox: thunderbird: Incorrect boundary conditions in the Graphics component (CVE-2026-16357) firefox: thunderbird: Sandbox escape due to use-after-free in the DOM: Navigation component (CVE-2026-16351) firefox: thunderbird: Privilege escalation in the DOM: Navigation component (CVE-2026-16371) firefox: thunderbird: Privilege escalation in the DOM: Content Processes component (CVE-2026-16379) firefox: thunderbird: Information disclosure in the Graphics: ImageLib component (CVE-2026-16354) firefox: thunderbird: Information disclosure in the Framework component in DevTools (CVE-2026-16374) firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: GMP component (CVE-2026-16359) firefox: thunderbird: Mitigation bypass in the DOM: Networking component (CVE-2026-16383) firefox: thunderbird: Integer overflow in the JavaScript: WebAssembly component (CVE-2026-16369) firefox: thunderbird: Invalid pointer in the DOM: Bindings (WebIDL) component (CVE-2026-16353) firefox: thunderbird: Privilege escalation in WebExtensions (CVE-2026-16396) firefox: thunderbird: Information disclosure in the Networking: WebSockets component (CVE-2026-16405) thunderbird: Off-by-one out of bounds read in MIME header parser for forwarding (CVE-2026-14899) 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.

Red Hat

Affected Software

20 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for IBM z Systems
Red Hat Red Hat Enterprise Linux for Power, little endian
Red Hat Red Hat Enterprise Linux for ARM 64
Red Hat Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for x86_64
redhat/thunderbird<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird-debuginfo<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird-debugsource<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird-debuginfo<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird-debugsource<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird-debuginfo<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird-debugsource<140.13.0-1.el8_10
140.13.0-1.el8_10
redhat/thunderbird<140.13.0-1.el8_10.aa
140.13.0-1.el8_10.aa
redhat/thunderbird-debuginfo<140.13.0-1.el8_10.aa
140.13.0-1.el8_10.aa
redhat/thunderbird-debugsource<140.13.0-1.el8_10.aa
140.13.0-1.el8_10.aa

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/thunderbird to a version that resolves this vulnerability.

    Fixed in 140.13.0-1.el8_10
  2. Upgrade

    Upgrade redhat/thunderbird-debuginfo to a version that resolves this vulnerability.

    Fixed in 140.13.0-1.el8_10
  3. Upgrade

    Upgrade redhat/thunderbird-debugsource to a version that resolves this vulnerability.

    Fixed in 140.13.0-1.el8_10
  4. Upgrade

    Upgrade redhat/thunderbird to a version that resolves this vulnerability.

    Fixed in 140.13.0-1.el8_10.aa
  5. Upgrade

    Upgrade redhat/thunderbird-debuginfo to a version that resolves this vulnerability.

    Fixed in 140.13.0-1.el8_10.aa
  6. Upgrade

    Upgrade redhat/thunderbird-debugsource to a version that resolves this vulnerability.

    Fixed in 140.13.0-1.el8_10.aa

Event History

Aug 4, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·07:10 AM
Data Sourced
via Red Hat·07:10 AM
Severity
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