No exploitation reportedFix available

CVE-2023-6135

Q: Is CVE-2023-6135 actively exploited?

Active exploitation of CVE-2023-6135 has not been confirmed. Its EPSS score was 0.7% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2023-6135?

CVE-2023-6135 has a CVSS v3 base score of 4.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

No exploitation reported by the sources we read.

Published2023-12-19
Fixed in121.0
WeaknessCWE-203

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC

2023-12-1914:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-6135?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-6135?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Mozilla firefox

Branch	Affected	Fixed in	Source
121.0	< 121.0	121.0	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

nsprAlmaLinux:9all versions · fixed in 4.35.0-6.el9_3and 1 other package
nssAlmaLinux:9all versions · fixed in 3.90.0-6.el9_3and 9 other packages
nssAlmaLinux:8all versions · fixed in 3.90.0-6.el8_9and 9 other packages

Full record on NVD

Fix

Update Mozilla firefox to 121.0

Advisories and patches

www.mozilla.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2024-08-27
OpenCVESSVC decisionnone—
NVDCVSS 3.14.3read 2026-10-23
NVDweakness (CWE)CWE-203read 2026-10-23
FIRST EPSSEPSS score0.7 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Published: 2023-12-19
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2023-6135?

Is CVE-2023-6135 actively exploited?

Active exploitation of CVE-2023-6135 has not been confirmed. Its EPSS score was 0.7% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-6135?

CVE-2023-6135 has a CVSS v3 base score of 4.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

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