CVE-2018-5124

FAUCET Score

CVE-2018-5124 is a medium-severity vulnerability affecting Mozilla Firefox versions prior to 58.0.1, where unsanitized output in the browser UI allows HTML tags to remain, potentially leading to arbitrary code execution. The attack requires user interaction, but can result in low impact to confidentiality and integrity. While there is no known active exploitation or public exploit code, the vulnerability has garnered significant community discussion and media coverage, indicating awareness of its potential.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		< 58.0.1CPE matchmatch criteria	cpe:2.3:a:mozilla:firefox::::::::

CVSS Data

CVSS version used by this source: 3.0

6.1MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

NONE

Exploitability Score

2.8

Impact Score

2.7

CvssVersion

3.0

Exploit Intelligence

EPSS Score

1.01%

Probability of exploitation in next 30 days

EPSS Percentile

59.6%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.0101 is in the 72nd percentile among its peer group of 26,221 CVEs.

Social Chatter

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

Media Mentions

The average CVE in this peer group has 0.1 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-2018-5124Important

firefox: Unsanitized output in browser UI can lead to arbitrary code execution

Jan 29, 2018

References

mozilla.org / en-US/security/advisories/mfsa2018-05

Vendor Advisory