CVE-2026-84637
published 2026-09-01CVE-2026-84637: Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal…
PriorityP349critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.63%
48.5th percentile
Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | thunderbird | < Thunderbird 153.2 | Thunderbird 153.2 |
| mozilla | thunderbird | < 153.2.0 | 153.2.0 |
| mozilla | thunderbird | — | — |
| mozilla | thunderbird | >= 154.0 < 155.0 | 155.0 |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat8.8HIGH
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GHSA
Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections.
ghsa_unreviewed·2026-09-02
CVE-2026-84637 Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections.
Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2.
VulDB
Mozilla Thunderbird up to 153/153.1 Calendar Invitation code injection
vuldb·2026-09-01
CVE-2026-84637 [LOW] Mozilla Thunderbird up to 153/153.1 Calendar Invitation code injection
A vulnerability was found in Mozilla Thunderbird up to 153/153.1. It has been classified as problematic. Impacted is an unknown function of the component Calendar Invitation. Performing a manipulation results in code injection.
This vulnerability is identified as CVE-2026-84637. The attack can be initiated remotely. There is not any exploit available.
Upgrading the affected component is recommended.
Red Hat
thunderbird: Thunderbird: Arbitrary code execution via malicious calendar invitation attachments
vendor_redhat·2026-09-01·CVSS 8.8
CVE-2026-84637 [HIGH] CWE-59 thunderbird: Thunderbird: Arbitrary code execution via malicious calendar invitation attachments
thunderbird: Thunderbird: Arbitrary code execution via malicious calendar invitation attachments
A flaw was found in Thunderbird. Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows systems. This bypasses Thunderbird's built-in protections for executable attachments, potentially leading to arbitrary code execution. Additionally, the attachment could be disguised with a misleading filename, increasing the risk of exploitation.
Package: thunderbird (Red Hat Enterprise Linux 10) - Affected
Package: thunderbird (Red Hat Enterprise Linux 8) - Affected
Package: thunderbird (Red Hat Enterprise Linux 9) - Affected
Mozilla
Mozilla Foundation Security Advisory 2026-88: CVE-2026-84637
vendor_mozilla
CVE-2026-84637 Mozilla Foundation Security Advisory 2026-88: CVE-2026-84637
Mozilla Foundation Security Advisory 2026-88
CVE: CVE-2026-84637
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153.2
No detection rules found.
No public exploits indexed.
2026-09-01
Published