CVE•Published 2026-05-27•Modified 2026-06-02•1 article on news•6 live references•NVD data
CVE-2026-6957Mattermost · Legal_hold
Vulnerability data via NVD (ingested)
CVSS v3.1
8.0
HIGH
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS percentile
—
Weaknesses (CWE)
Description
Mattermost Plugins versions <=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659
Timeline
Published 2026-05-27
Modified 2026-06-02
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).
Shodan · vuln tag0 hosts
vuln:CVE-2026-6957Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · product
product:"Mattermost Legal Hold"All exposed Mattermost Legal Hold instances — cross-reference with the CVE's affected-version range.
Shodan · banner/body mention
http.html:"Legal Hold"HTTP body or banner mentions "Legal Hold" — catches deploys Shodan didn't identify as a product.
More intel sources (5)
Shodan report
vuln:CVE-2026-6957Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-6957Censys host search filtered to this CVE id.
grep.app
CVE-2026-6957Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-6957GitHub code search for direct mentions.
Google dork
"CVE-2026-6957" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-6957 on GitHub.