Is there a public exploit for CVE-2024-3863?

No public exploit for CVE-2024-3863 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2024-3863?

CVE-2024-3863 scores CVSS 9.8 (v3.1), rated critical. EPSS puts the chance of exploitation in the next 30 days at 0.81%.

What does CVE-2024-3863 affect?

CVE-2024-3863 affects Mozilla Thunderbird, Firefox ESR, Firefox.

9.8 Critical

The executable file warning was not presented when downloading .xrm-ms files.

CVE-2024-3863

The executable file warning was not presented when downloading .xrm-ms files. Note: This issue only affected Windows operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 125, Firefox ESR < 115.10, and Thunderbird < 115.10.

Assessment

CVSS: 9.8 (v3.1)
Severity: Critical
EPSS: 0.81% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 16 April 2024
Last updated: 4 November 2026
Affected: Mozilla · Firefox · Firefox ESR · Thunderbird
Assigner: mozilla

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

At the source

EUVD (ENISA)

References

Community proofs of concept

No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.

Submit a proof of concept

Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.

Title *

Proof of concept *

Write-up (optional)

Affected versions (optional)

Name or handle (optional)

References (optional, one URL per line)

Licence for your contribution *

Private contact (optional, never shown)

Before you submit * This vulnerability is already publicly disclosed (it has a published CVE). This material comes only from testing I was authorised to perform. I have the legal right to publish this content and am not breaching any agreement by doing so. It contains no live credentials, personal data, or anything targeting systems I am not authorised to test. I understand it will be reviewed before it appears publicly and may be rejected. I agree to the submission terms.

What is 8 + 6? *

Query this programmatically

Agents can read this through the MCP endpoint, or over HTTP:

curl https://cve.zerocrew.in/api/cve/CVE-2024-3863