Back to Security Advisories
High 2026-08-04

Thunderbird Security Update — AlmaLinux 8 (ALSA-2026:49922)

AlmaLinux 8

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: Mitigat…

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: Mitigat…

Type:
security

Severity:
important

Release date:
2026-08-04

Description:
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.

Updated packages listed below:

Architecture Package Checksum
aarch64 thunderbird-140.13.0-1.el8_10.alma.1.aarch64.rpm 39557e2a4a32842d17518a1cb55b87f9bd10c4439802b2dbd0fe13e2ca5c3ab5
ppc64le thunderbird-140.13.0-1.el8_10.alma.1.ppc64le.rpm 77db600bc5f090cec6d9df5c1587fdfacf203f017b4e3ad2c8c06facf9d92e37
s390x thunderbird-140.13.0-1.el8_10.alma.1.s390x.rpm 91e9f632c2ca03bc5015a29f2514c0e74b501325842541406f39b979a6258f85
x86_64 thunderbird-140.13.0-1.el8_10.alma.1.x86_64.rpm dbefd9a3503d75ce7269eda45f49512a64a7e42f74f2ae973961505c688f0179

Notes:
This page is generated automatically from Red Hat security data and has not been checked for errors. For clarification or corrections please contact the AlmaLinux Packaging Team.

More Information

Check your system for vulnerabilities

Select your product and operating system to see the exact fix commands that apply to you.

Check Your System