Linux · Security advisory · August 4, 2026

ALSA-2026:49921: thunderbird security update

ALSA-2026:49921, released August 4, 2026, fixes 33 CVEs in thunderbird (version 140.13.0-1.el9_8.alma.1). None of them is reported as exploited. Patch Radar priority: Urgent.

Urgent
CVEs closed
33
22 rated Critical
Exploited
0
None reported
Exploitation more likely
0
Vendor assessment
Highest EPSS
0.0087
58th percentile

Priority of the 33 CVEs

Patch now 0 Urgent 22 High 11 Routine 0

Fixed package versions

ProductReleaseFixed in
thunderbirdalmalinux 9140.13.0-1.el9_8.alma.1

CVEs this fix closes

PriorityCVETitleImpactCVSSEPSSExploitation
Urgent CVE-2026-16357 Incorrect boundary conditions in the Graphics component 9.8 0.0087 None reported
Urgent CVE-2026-16363 JIT miscompilation in the JavaScript: WebAssembly component 9.8 0.0064 None reported
Urgent CVE-2026-16369 Integer overflow in the JavaScript: WebAssembly component 9.8 0.0064 None reported
Urgent CVE-2026-16412 Memory safety bugs fixed in Thunderbird ESR 140.13 and Thunderbird 153 9.8 0.0061 None reported
Urgent CVE-2026-16350 Incorrect boundary conditions in the Audio/Video: cubeb component 9.8 0.0060 None reported
Urgent CVE-2026-16353 Invalid pointer in the DOM: Bindings (WebIDL) component 9.8 0.0060 None reported
Urgent CVE-2026-16355 JIT miscompilation in the JavaScript Engine: JIT component 9.8 0.0060 None reported
Urgent CVE-2026-16351 Sandbox escape due to use-after-free in the DOM: Navigation component 9.8 0.0058 None reported
Urgent CVE-2026-16352 Sandbox escape due to use-after-free in the Disability Access APIs component 9.8 0.0058 None reported
Urgent CVE-2026-16356 Sandbox escape due to use-after-free in the Disability Access APIs component 9.8 0.0058 None reported
Urgent CVE-2026-16361 Memory safety bugs fixed in Thunderbird ESR 140.13 9.8 0.0057 None reported
Urgent CVE-2026-16377 Mitigation bypass in the PDF Viewer component 9.8 0.0057 None reported
Urgent CVE-2026-16383 Mitigation bypass in the DOM: Networking component 9.8 0.0057 None reported
Urgent CVE-2026-16359 Incorrect boundary conditions in the Audio/Video: GMP component 9.1 0.0047 None reported
Urgent CVE-2026-16360 Memory safety bugs fixed in Thunderbird ESR 140.13 and Thunderbird 153 9.8 0.0047 None reported
Urgent CVE-2026-16390 Mitigation bypass in the Enterprise Policies component 9.1 0.0044 None reported
Urgent CVE-2026-16368 Incorrect boundary conditions in the JavaScript: WebAssembly component 9.8 0.0039 None reported
Urgent CVE-2026-16358 Site isolation issue in the Graphics: WebRender component 9.8 0.0030 None reported
Urgent CVE-2026-16349 Same-origin policy bypass in the DOM: Navigation component 9.8 0.0030 None reported
Urgent CVE-2026-16375 Site isolation issue in the Networking: HTTP component 9.8 0.0029 None reported
Urgent CVE-2026-16387 Site isolation issue in the Networking component 9.8 0.0028 None reported
Urgent CVE-2026-16381 Same-origin policy bypass in the Networking: DNS component 9.1 0.0023 None reported
High CVE-2026-14899 Off-by-one out of bounds read in MIME header parser for forwarding 8.8 0.0047 None reported
High CVE-2026-16354 Information disclosure in the Graphics: ImageLib component 8.8 0.0047 None reported
High CVE-2026-16396 Privilege escalation in WebExtensions 8.8 0.0045 None reported
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