What is CVE-2023-6135?

CVE-2023-6135 is a medium-severity vulnerability in Mozilla Firefox, classified under Observable Discrepancy. CVSS score: 4.3/10. Published 2023-12-19.

How severe is CVE-2023-6135?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in Mozilla Firefox

CVE-2023-6135

Multiple NSS NIST curves were susceptible to a side-channel attack known as "Minerva". This attack could potentially allow an attacker to recover the private key. This vulnerability affects Firefox < 121.

Published 2023-12-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.9th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Mozilla Firefox — versions unspecified

Weakness classification (CWE)

CWE-203 — Observable Discrepancy

References

bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
www.mozilla.org/security/advisories/mfsa2023-56/ (Vendor Advisory)
security.gentoo.org/glsa/202401-10

Frequently asked questions

What is CVE-2023-6135?: CVE-2023-6135 is a medium-severity vulnerability in Mozilla Firefox, classified under Observable Discrepancy. CVSS score: 4.3/10. Published 2023-12-19.
How severe is CVE-2023-6135?: Medium severity. CVSS v3 base score is 4.3 out of 10.