Mattermost 6.4
Mattermost 6.4
The Mattermost 6.4 reached end of service life on May 15, 2022 — Mattermost no longer ships security patches or fixes for it. Our third-party support keeps it safe to run: 24/7 engineers manage issues, remediate vulnerabilities, and help you maintain compliance.
24/7 engineers own your Mattermost 6.4 incidents end to end.
Mitigation and patch-around guidance when the vendor no longer ships fixes.
Controls evidence and documentation that keep auditors satisfied.
Specifications
- product
- mattermost
- release
- 6.4
- product Label
- Mattermost
- release Label
- 6.4
- codename
- lts
- latest Version
- 6.4.3
- release Date
- 2022-02-15
- maintained
- source Url
- https://endoflife.date/mattermost
Lifecycle Dates
- End of Service Life
- May 15, 2022
- Last OEM Support
- May 15, 2022
OEM vs. 3rd Party Support
See how third-party support compares to the vendor contract for Mattermost 6.4 — monitoring, break/fix, vulnerability work, operations and compliance, before and after EOSL.
| Feature | OEM Support | 3rd Party Support |
|---|---|---|
| Post-EOSL Support | ||
| Break/Fix Support | Until EOSL | |
| 24/7 Monitoring | ||
| Vulnerability Scanning & Remediation | ||
| Managed Operations | ||
| Procedure & Configuration Review | ||
| Compliance & Audit Documentation | Limited | |
| Discounted Migration to Other Platforms |
Why Choose 3rd Party Support for Mattermost 6.4?
Vulnerability Remediation
Scanning, mitigation and patch-around guidance for Mattermost 6.4 when the vendor no longer ships fixes.
Compliance Maintenance
Procedure review, controls evidence and the documentation auditors ask for — maintained continuously, not scrambled at audit time.
24/7 Expert Support
Engineers who know this release monitor, manage and fix issues around the clock — break/fix to managed operations.
Mattermost 6.4 Support: Frequently Asked Questions
Is the Mattermost 6.4 still supported?
Mattermost ended support for the Mattermost 6.4 on May 15, 2022 — no more patches or fixes from the vendor. Third-party support keeps it covered: our engineers manage issues, remediate vulnerabilities, and help you maintain compliance for as long as you run it.
When is the Mattermost 6.4 end of service life (EOSL) date?
Mattermost lists the end of service life for the Mattermost 6.4 as May 15, 2022.
Can I keep using the Mattermost 6.4 after its EOSL date?
Yes. EOSL means Mattermost stops issuing patches and support — the software itself keeps running. Third-party support covers it from there: issue management, security vulnerability remediation, and the compliance documentation auditors ask for, for as long as you choose to run it.
How much does third-party support for the Mattermost 6.4 cost?
Typically 40-70% below the OEM maintenance renewal price. Exact pricing depends on quantity, service level and location — request a quote and we respond within 24 hours.
Known Vulnerabilities Affecting Mattermost 6.4
54 published CVEs affect the Mattermost 6.4, including 4 rated critical or high severity. Mattermost no longer ships security patches for this release — our engineers provide mitigation guidance, workarounds and hardening support.
| CVE | Severity | CVSS | Published | Summary |
|---|---|---|---|---|
| CVE-2023-45316 | HIGH | 7.3 | Dec 12, 2023 | Mattermost fails to validate if a relative path is passed in /plugins/playbooks/api/v0/telemetry/run/<telem_run_id> as a telemetry run ID, allowing an attacker to use a path traversal payload that points to a different endpoint leading to a CSRF attack. |
| CVE-2023-1776 | HIGH | 7.3 | Mar 31, 2023 | Boards in Mattermost allows an attacker to upload a malicious SVG image file as an attachment to a card and share it using a direct link to the file. |
| CVE-2023-1831 | HIGH | 7.2 | Apr 17, 2023 | Mattermost fails to redact from audit logs the user password during user creation and the user password hash in other operations if the experimental audit logging configuration was enabled (ExperimentalAuditSettings section in config). |
| CVE-2023-6458 | HIGH | 7.1 | Dec 6, 2023 | Mattermost webapp fails to validate route parameters in/<TEAM_NAME>/channels/<CHANNEL_NAME> allowing an attacker to perform a client-side path traversal. |
| CVE-2025-55070 | MEDIUM | 6.5 | Nov 14, 2025 | Mattermost versions <11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events |
| CVE-2023-46701 | MEDIUM | 6.5 | Dec 12, 2023 | Mattermost fails to perform authorization checks in the /plugins/playbooks/api/v0/runs/add-to-timeline-dialog endpoint of the Playbooks plugin allowing an attacker to get limited information about a post if they know the post ID |
| CVE-2023-1777 | MEDIUM | 6.5 | Mar 31, 2023 | Mattermost allows an attacker to request a preview of an existing message when creating a new message via the createPost API call, disclosing the contents of the linked message. |
| CVE-2022-2401 | MEDIUM | 6.5 | Jul 14, 2022 | Unrestricted information disclosure of all users in Mattermost version 6.7.0 and earlier allows team members to access some sensitive information by directly accessing the APIs. |
| CVE-2022-2366 | MEDIUM | 5.6 | Jul 12, 2022 | Incorrect default configuration for trusted IP header in Mattermost version 6.7.0 and earlier allows attacker to bypass some of the rate limitations in place or use manipulated IPs for audit logging via manipulating the request headers. |
| CVE-2025-27936 | MEDIUM | 5.3 | Apr 16, 2025 | Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison. |
| CVE-2023-6459 | MEDIUM | 5.3 | Dec 6, 2023 | Mattermost is grouping calls in the /metrics endpoint by id and reports that id in the response. Since this id is the channelID, the public /metrics endpoint is revealing channelIDs. |
| CVE-2023-2515 | MEDIUM | 4.7 | May 12, 2023 | Mattermost fails to restrict a user with permissions to edit other users and to create personal access tokens from elevating their privileges to system admin |
| CVE-2022-1384 | MEDIUM | 4.7 | Apr 19, 2022 | Mattermost version 6.4.x and earlier fails to properly check the plugin version when a plugin is installed from the Marketplace, which allows an authenticated and an authorized user to install and exploit an old plugin version from the Marketplace which might have known vulnerabilities. |
| CVE-2026-2461 | MEDIUM | 4.3 | Mar 16, 2026 | Mattermost Plugins versions <=11.3 11.0.3 11.2.2 10.10.11.0 fail to implement authorisation checks on comment block modifications, which allows an authorised attacker with editor permission to modify comments created by other board members. Mattermost Advisory ID: MMSA-2025-00559 |
| CVE-2025-11776 | MEDIUM | 4.3 | Nov 14, 2025 | Mattermost versions <11 fail to properly restrict access to archived channel search API which allows guest users to discover archived public channels via the `/api/v4/teams/{team_id}/channels/search_archived` endpoint |
| CVE-2024-1888 | MEDIUM | 4.3 | Feb 29, 2024 | Mattermost fails to check the "invite_guest" permission when inviting guests of other teams to a team, allowing a member with permissions to add other members but not to add guests to add a guest to a team as long as the guest was already a guest in another team of the server |
| CVE-2024-24988 | MEDIUM | 4.3 | Feb 29, 2024 | Mattermost fails to properly validate the length of the emoji value in the custom user status, allowing an attacker to send multiple times a very long string as an emoji value causing high resource consumption and possibly crashing the server. |
| CVE-2024-23493 | MEDIUM | 4.3 | Feb 29, 2024 | Mattermost fails to properly authorize the requests fetching team associated AD/LDAP groups, allowing a user to fetch details of AD/LDAP groups of a team that they are not a member of. |
| CVE-2024-1887 | MEDIUM | 4.3 | Feb 29, 2024 | Mattermost fails to check if compliance export is enabled when fetching posts of public channels allowing a user that is not a member of the public channel to fetch the posts, which will not be audited in the compliance export. |
| CVE-2024-1402 | MEDIUM | 4.3 | Feb 9, 2024 | Mattermost fails to check if a custom emoji reaction exists when sending it to a post and to limit the amount of custom emojis allowed to be added in a post, allowing an attacker sending a huge amount of non-existent custom emojis in a post to crash the mobile app of a user seeing the post and to crash the server due to overloading when clients attempt to retrive the aforementioned post. |
Showing the 20 most severe of 54 known CVEs.
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