What is CVE-2023-25731?

CVE-2023-25731 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Validation of Specified Quantity in Input. CVSS score: 8.8/10. Published 2023-06-02.

How severe is CVE-2023-25731?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Mozilla Firefox

CVE-2023-25731

Due to URL previews in the network panel of developer tools improperly storing URLs, query parameters could potentially be used to overwrite global objects in privileged code. This vulnerability affects Firefox < 110.

Published 2023-06-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (44.3th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Mozilla Firefox — versions unspecified

Weakness classification (CWE)

CWE-1284 — Improper Validation of Specified Quantity in Input

References

www.mozilla.org/security/advisories/mfsa2023-05/ (Vendor Advisory)
bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)

Frequently asked questions

What is CVE-2023-25731?: CVE-2023-25731 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Validation of Specified Quantity in Input. CVSS score: 8.8/10. Published 2023-06-02.
How severe is CVE-2023-25731?: High severity. CVSS v3 base score is 8.8 out of 10.