Attachment of deleted message in a thread remains accessible and downloadable
Priority LOW 20CWE-862Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-862.
Summary
Mattermost fails to delete the attachments when deleting a message in a thread allowing a simple user to still be able to access and download the attachment of a deleted message
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00399 34th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 7.8.8, 7.9.6, 7.10.4 github.com/mattermost/mattermost-server/v6 (Go): 7.9.6, 7.10.4, 7.8.8
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mattermost | Mattermost | up to 7.8.7; up to 7.9.5; up to 7.10.3 | 7.8.8, 7.9.6, 7.10.4 | Patch available | CNA |
| — | github.com/mattermost/mattermost-server/v6 (Go) | 7.9.0 to before 7.9.6 | 7.9.6 | Patch available | GHSA-g3v6-r8p9-wxg9 |
| — | github.com/mattermost/mattermost-server/v6 (Go) | 7.10.0 to before 7.10.4 | 7.10.4 | Patch available | GHSA-g3v6-r8p9-wxg9 |
| — | github.com/mattermost/mattermost-server/v6 (Go) | before 7.8.8 | 7.8.8 | Patch available | GHSA-g3v6-r8p9-wxg9 |
- Mattermost VendorMattermost Affected up to 7.8.7; up to 7.9.5; up to 7.10.3 Fixed in 7.8.8, 7.9.6, 7.10.4 Patch available CNA
- github.com/mattermost/mattermost-server/v6 (Go) Vendor— Affected 7.9.0 to before 7.9.6 Fixed in 7.9.6 Patch available GHSA-g3v6-r8p9-wxg9
- github.com/mattermost/mattermost-server/v6 (Go) Vendor— Affected 7.10.0 to before 7.10.4 Fixed in 7.10.4 Patch available GHSA-g3v6-r8p9-wxg9
- github.com/mattermost/mattermost-server/v6 (Go) Vendor— Affected before 7.8.8 Fixed in 7.8.8 Patch available GHSA-g3v6-r8p9-wxg9
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | 7.8.0 to before 7.8.8; 7.9.0 to before 7.9.6; 7.10.0 to before 7.10.4 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* Versions 7.8.0 to before 7.8.8; 7.9.0 to before 7.9.6; 7.10.0 to before 7.10.4 Vulnerable ·Mattermost
Remediation
- Fix · CNA Mattermost (Mattermost) Fixed in 7.8.8, 7.9.6, 7.10.4
- Fix · GHSA-g3v6-r8p9-wxg9 github.com/mattermost/mattermost-server/v6 (Go) Fixed in 7.9.6 Advisory →
- Fix · GHSA-g3v6-r8p9-wxg9 github.com/mattermost/mattermost-server/v6 (Go) Fixed in 7.10.4 Advisory →
- Fix · GHSA-g3v6-r8p9-wxg9 github.com/mattermost/mattermost-server/v6 (Go) Fixed in 7.8.8 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2023-4105
- 2026-10-03 Alias added: GHSA-g3v6-r8p9-wxg9
References
More Mattermost vulnerabilities
- TI-2024-26695 Malicious remote can invite itself to an arbitrary local channel CVSS 3.1CRITICAL 9.6
- TI-2023-02056 Oauth authorization codes do not expire when deauthorizing an oauth2 app CVSS 3.1CRITICAL 9.1
- TI-2019-15069 An issue was discovered in Mattermost Mobile Apps before 1.26.0. CVSS 3.1CRITICAL 9.1
- TI-2024-26233 Malicious remote can add users to arbitrary teams and channels CVSS 3.1HIGH 8.7
- TI-2024-26746 Permanently local data deletion by malicious remote CVSS 3.1HIGH 8.7
- TI-2023-06508 Injection in Mattermost CVSS 3.1HIGH 8.8
Sources
- CVE-2023-4105 · CVE Program
- CVE-2023-4105 · NVD
- FIRST EPSS
- GHSA-g3v6-r8p9-wxg9 · GitHub Advisory Database · CC BY 4.0
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