High

Downloads Panel Spoofing in Mozilla Firefox and Thunderbird

IdentifiersCVE-2025-14327CWE-451

CVE-2025-14327 is a spoofing vulnerability in the Downloads Panel component of Mozilla Firefox and Thunderbird. The issue affects Firefox versions prior to 146, Thunderbird versions prior to 146, Firefox ESR prior to 140.7, and Thunderbird prior to 140.7. Based on the available advisory text, the flaw allows user interface spoofing within the Downloads Panel, which could mislead users about download-related information, status, origin, or actions. The provided material does not include the specific vulnerable function or root-cause implementation details.

For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

Start free trial

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can enable UI spoofing in the Downloads Panel, potentially deceiving users into trusting malicious or misleading download-related content or actions. This could facilitate social engineering, unsafe file execution, or other follow-on compromise depending on user behavior. The supplied advisories characterize the issue as spoofing rather than direct code execution, and no in-the-wild exploitation is reported in the provided content.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure to untrusted web content and downloads. Restrict browsing to trusted sites where feasible, limit or disable downloads through enterprise policy if operationally acceptable, and use web filtering, DNS filtering, and application allowlisting to reduce delivery and execution of malicious content. Additional containment controls such as OS-level sandboxing or mandatory access controls may further reduce risk, but the primary mitigation is to apply the vendor update.

Remediation

Patch, then assume compromise.

Upgrade affected Mozilla products to fixed versions. Specifically, upgrade Firefox to 146 or later, Thunderbird to 146 or later, Firefox ESR to 140.7 or later, and Thunderbird ESR-equivalent fixed builds to 140.7 or later as provided by Mozilla or downstream vendors. For Debian, apply the relevant security updates, including firefox-esr 140.7.0esr-1~deb12u1 or 140.7.0esr-1~deb13u1 where applicable.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

MozillaFirefoxapplication

MozillaThunderbirdapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

15 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

15 SOURCESView more in app

cisecurity blog msisca and eiisacNews

Dec 9, 2025

Multiple Vulnerabilities in Mozilla Products Could Allow for Arbitrary Code Execution

A spoofing vulnerability in the Downloads Panel component of Mozilla products, potentially allowing attackers to mislead users.

unclassifiedNews

Dec 9, 2025

Security Vulnerabilities fixed in Firefox 146

A spoofing vulnerability in the Downloads Panel component of Firefox, which could allow an attacker to mislead users about the origin or nature of downloaded files.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

Start free trial

Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity9