What is CVE-2023-6458?

CVE-2023-6458 is a high-severity vulnerability in Mattermost, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 7.1/10. Published 2023-12-06.

How severe is CVE-2023-6458?

High severity. CVSS v3 base score is 7.1 out of 10.

Is CVE-2023-6458 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Path Traversal in Mattermost

CVE-2023-6458

Mattermost webapp fails to validate route parameters in/<TEAM_NAME>/channels/<CHANNEL_NAME> allowing an attacker to perform a client-side path traversal.

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

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:H/A:L.

EPSS exploit prediction

EPSS: 0.006 (48.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.8% 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

Mattermost — versions 0, 9.1.2, 9.0.3
Mattermost Server

Weakness classification (CWE)

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

mattermost.com/security-updates (Vendor Advisory)

Frequently asked questions

What is CVE-2023-6458?: CVE-2023-6458 is a high-severity vulnerability in Mattermost, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 7.1/10. Published 2023-12-06.
How severe is CVE-2023-6458?: High severity. CVSS v3 base score is 7.1 out of 10.
Is CVE-2023-6458 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.