SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2017-5455

The internal feed reader APIs that crossed the sandbox barrier allowed for a sandbox escape and escalation of privilege if combined with another vulnerability that resulted in remote code execution inside the sandboxed process.

HIGH 7.5EPSS 3.43%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (3.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

The internal feed reader APIs that crossed the sandbox barrier allowed for a sandbox escape and escalation of privilege if combined with another vulnerability that resulted in remote code execution inside the sandboxed process. This vulnerability affects Firefox ESR < 52.1 and Firefox < 53.

CVSS 3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
3.43% probability · 89th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Affected
redhat/enterprise linux · redhat/enterprise linux desktop · redhat/enterprise linux server · redhat/enterprise linux server aus · redhat/enterprise linux server eus · redhat/enterprise linux workstation · mozilla/firefox
Source
security@mozilla.org
EPSS trend
0%3%5%27 October 2026: 3.43%27 October 202627 October 2026

EPSS 3.4% 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.