CVE•Published 2026-10-16•Modified 2026-10-16•0 articles on news•3 live references•NVD data

CVE-2026-19603

Vulnerability data via NVD (ingested)

CVSS v3.1

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS percentile

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Weaknesses (CWE)

CWE-201Insertion of Sensitive Information Into Sent Data

Description

Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to sanitize the active channel field returned by the user status API endpoints, which allows an authenticated user to learn the channel ID of a private channel another user is actively viewing via the status endpoints, without being a member of that channel. Mattermost Advisory ID: MMSA-2026-00765

Timeline

Published 2026-10-16

Modified 2026-10-16

External references

NVD MITRE VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-19603

Hosts Shodan has explicitly fingerprinted as vulnerable.

More intel sources (5)

Shodan report

vuln:CVE-2026-19603

Country / ASN / product breakdown for the vuln query.

Censys

vulnerabilities.cve_id: CVE-2026-19603

Censys host search filtered to this CVE id.

grep.app

CVE-2026-19603