SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2022-22761

This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.

HIGH 8.8EPSS 0.78%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.78%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Web-accessible extension pages (pages with a moz-extension:// scheme) were not correctly enforcing the frame-ancestors directive when it was used in the Web Extension's Content Security Policy. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.78% probability · 56th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-693
Affected
mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
Source
security@mozilla.org
EPSS trend
0%3%5%26 October 2026: 0.78%26 October 202626 October 2026

EPSS 0.8% 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.