CVE•Published 2026-05-22•Modified 2026-07-23•0 articles on news•6 live references•NVD data
CVE-2026-4646Mattermost · Mattermost_server
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:N/I:N/A:L
EPSS percentile
16
Exploit Prediction Scoring System · top 84% of all CVEs
Weaknesses (CWE)
Description
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint.. Mattermost Advisory ID: MMSA-2026-00638
Timeline
Published 2026-05-22
Modified 2026-07-23
External references
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). Live host counts are a Premium feature.
Shodan · vuln tag
vuln:CVE-2026-4646Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · product
product:"Mattermost Mattermost Server"All exposed Mattermost Mattermost Server instances — cross-reference with the CVE's affected-version range.
Shodan · banner/body mention
http.html:"Mattermost Server"HTTP body or banner mentions "Mattermost Server" — catches deploys Shodan didn't identify as a product.
More intel sources (5)
Shodan report
vuln:CVE-2026-4646Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-4646Censys host search filtered to this CVE id.
grep.app
CVE-2026-4646Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-4646GitHub code search for direct mentions.
Google dork
"CVE-2026-4646" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub (2)
We haven't classified any articles referencing CVE-2026-4646 yet. The external references above still apply.