SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-5723

An attacker with temporary script access to a site could have set a cookie containing invalid characters using `document.cookie` that could have led to unknown errors.

MEDIUM 5.3EPSS 0.70%

Does this matter?

Lower severity and a low EPSS score (0.70%). Track it; it rarely justifies an emergency change on its own.

Description

An attacker with temporary script access to a site could have set a cookie containing invalid characters using `document.cookie` that could have led to unknown errors. This vulnerability affects Firefox < 119.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
0.70% probability · 53th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Affected
mozilla/firefox
Source
security@mozilla.org
EPSS trend
0%3%5%26 October 2026: 0.70%26 October 202626 October 2026

EPSS 0.7% since 26 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.