Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2019-9801

16
FAUCET Score

CVE-2019-9801 describes a vulnerability in Firefox, Firefox ESR, and Thunderbird on Windows operating systems where the browser would incorrectly accept any registered Program ID as an external protocol handler, offering to launch local applications for matching URLs. This medium-severity vulnerability (CVSS 5.3) has a low attack complexity and could lead to unauthorized application launches, but not directly to confidentiality or availability impacts. There is no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
< 66.0CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
< 60.6CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
< 60.6CPE matchmatch criteria
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.0

5.3MEDIUM

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
1.4
CvssVersion
3.0

Exploit Intelligence

EPSS Score
1.31%
Probability of exploitation in next 30 days
EPSS Percentile
67.7%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0131 is in the 48th percentile among its peer group of 23,725 CVEs.

Social Chatter

No social media mentions found for this CVE.

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Patches (1)

mozillavendor investigatingvia nvd_reference
View patch

Vendor Advisories (1)

redhatCVE-2019-9801Moderate

Mozilla: Windows programs that are not 'URL Handlers' are exposed to web content

Mar 20, 2019

References

bugzilla.mozilla.org / show_bug.cgi
Issue TrackingPermissions RequiredVendor Advisory
mozilla.org / security/advisories/mfsa2019-07
Vendor Advisory
mozilla.org / security/advisories/mfsa2019-08
Vendor Advisory
mozilla.org / security/advisories/mfsa2019-11
Vendor Advisory