CVE-2026-16378
published 2026-07-21CVE-2026-16378: Other issue in the DOM: Copy & Paste and Drag & Drop component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
PriorityP340high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
0.31%
21.9th percentile
Other issue in the DOM: Copy & Paste and Drag & Drop component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 153 | Firefox 153 |
| mozilla | firefox | < 153.0.0 | 153.0.0 |
| mozilla | thunderbird | < Thunderbird 153 | Thunderbird 153 |
| mozilla | thunderbird | < 153.0 | 153.0 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vendor_redhat7.5HIGH
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Red Hat
firefox: thunderbird: Other issue in the DOM: Copy & Paste and Drag & Drop component
vendor_redhat·2026-07-21·CVSS 7.5
CVE-2026-16378 [HIGH] firefox: thunderbird: Other issue in the DOM: Copy & Paste and Drag & Drop component
firefox: thunderbird: Other issue in the DOM: Copy & Paste and Drag & Drop component
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Other issue in the DOM: Copy & Paste and Drag & Drop component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Not affected
Package: firefox (Red Hat Enterprise Linux 6) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 6) -
Mozilla
Mozilla Foundation Security Advisory 2026-68: CVE-2026-16378
vendor_mozilla
CVE-2026-16378 Mozilla Foundation Security Advisory 2026-68: CVE-2026-16378
Mozilla Foundation Security Advisory 2026-68
CVE: CVE-2026-16378
Product: Firefox
Impact: high
Fixed in: Firefox 153
Mozilla
Mozilla Foundation Security Advisory 2026-71: CVE-2026-16378
vendor_mozilla
CVE-2026-16378 Mozilla Foundation Security Advisory 2026-71: CVE-2026-16378
Mozilla Foundation Security Advisory 2026-71
CVE: CVE-2026-16378
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153
GHSA
Other issue in the DOM: Copy & Paste and Drag & Drop component.
ghsa_unreviewed·2026-07-21
CVE-2026-16378 [HIGH] CWE-20 Other issue in the DOM: Copy & Paste and Drag & Drop component.
Other issue in the DOM: Copy & Paste and Drag & Drop component. This vulnerability was fixed in Firefox 153.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-16378 firefox: thunderbird: Other issue in the DOM: Copy & Paste and Drag & Drop component
bugzilla·2026-07-21·CVSS 7.5
CVE-2026-16378 [HIGH] CVE-2026-16378 firefox: thunderbird: Other issue in the DOM: Copy & Paste and Drag & Drop component
CVE-2026-16378 firefox: thunderbird: Other issue in the DOM: Copy & Paste and Drag & Drop component
Other issue in the DOM: Copy & Paste and Drag & Drop component. This vulnerability was fixed in Firefox 153.
Bugzilla
A web page can cause Firefox to plant an attacker-named .url Internet Shortcut on the user's filesystem (via drag-out) whose URL= field carries an arbitrary scheme (file:// UNC, search-ms:, etc.), so
bugzilla·2026-05-12
CVE-2026-16378 A web page can cause Firefox to plant an attacker-named .url Internet Shortcut on the user's filesystem (via drag-out) whose URL= field carries an arbitrary scheme (file:// UNC, search-ms:, etc.), so
A web page can cause Firefox to plant an attacker-named .url Internet Shortcut on the user's filesystem (via drag-out) whose URL= field carries an arbitrary scheme (file:// UNC, search-ms:, etc.), so opening it executes attacker-chosen code.
## Summary
A web page can set `dataTransfer.setData("text/x-moz-url", "\n")`
in a `dragstart` handler. When the user drags that element to the Windows
shell, Firefox synthesizes a `.url` Internet Shortcut via
`CFSTR_FILEDESCRIPTOR` / `CFSTR_FILECONTENTS` containing
`[InternetShortcut]\r\nURL=` with **no scheme allowlist** — `file://`,
`file://UNC/...`, `search-ms:`, `ms-msdt:`, etc. all pass — and the dropped
file carries **no `Zone.Identifier` ADS** because Firefox does not advertise
`CFSTR_UNTRUSTEDDRAGDROP` on the `IDataObject`. SmartScreen / Atta
2026-07-21
Published