Mobile app freezes when receiving a post with hundreds of emojis
Priority LOW 20CWE-400Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
Mattermost Mobile fails to limit the maximum number of Markdown elements in a post allowing an attacker to send a post with hundreds of emojis to a channel and freeze the mobile app of users when viewing that particular channel.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00438 38th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 2.8.0
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 | before 2.8.0 | 2.8.0 | Patch available | CNA |
- Mattermost VendorMattermost Affected before 2.8.0 Fixed in 2.8.0 Patch available CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:android:*:* | before 2.8.0 | Vulnerable | Mattermost |
| cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:iphone_os:*:* | before 2.8.0 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:android:*:* Versions before 2.8.0 Vulnerable ·Mattermost
- cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:iphone_os:*:* Versions before 2.8.0 Vulnerable ·Mattermost
Remediation
- Fix · CNA Mattermost (Mattermost) Fixed in 2.8.0
Timeline
- 2026-10-02 Threatist record created from CVE-2023-5522
- 2026-10-03 Alias added: GHSA-2w9p-mj8f-374x
References
Advisory 1
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-2023-5522 · CVE Program
- CVE-2023-5522 · NVD
- FIRST EPSS
- GHSA-2w9p-mj8f-374x · GitHub Advisory Database · CC BY 4.0
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