SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-5112

This could allow the development tools panel for the extension to load a URL that it should not be able to access, including potentially privileged pages.

HIGH 7.5EPSS 1.95%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.95%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Development Tools panels of an extension are required to load URLs for the panels as relative URLs from the extension manifest file but this requirement was not enforced in all instances. This could allow the development tools panel for the extension to load a URL that it should not be able to access, including potentially privileged pages. This vulnerability affects Firefox < 58.

CVSS 3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.95% probability · 80th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-552
Affected
mozilla/firefox · canonical/ubuntu linux
Source
security@mozilla.org
EPSS trend
0%3%5%27 October 2026: 1.95%27 October 202627 October 2026

EPSS 1.9% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.