XSS in Mozilla Firefox

CVE-2022-40956

When injecting an HTML base element, some requests would ignore the CSP's base-uri settings and accept the injected element's base instead. This vulnerability affects Firefox ESR < 102.3, Thunderbird < 102.3, and Firefox < 105.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.009 (55.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2022-40956?
CVE-2022-40956 is a medium-severity vulnerability in Mozilla Firefox, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2022-12-22.
How severe is CVE-2022-40956?
Medium severity. CVSS v3 base score is 6.1 out of 10.