VulnerabilityModified
CVE-2018-21259
It allows attackers to cause a denial of service (application hang) via a malformed link in a channel.
MEDIUM 5.3EPSS 1.10%
Does this matter?
Lower severity and a low EPSS score (1.10%). Track it; it rarely justifies an emergency change on its own.
Description
An issue was discovered in Mattermost Server before 4.10.1, 4.9.4, and 4.8.2. It allows attackers to cause a denial of service (application hang) via a malformed link in a channel.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- EPSS
- 1.10% probability · 65th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- mattermost/mattermost server
- Source
- cve@mitre.org
EPSS 1.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://mattermost.com/security-updates/Vendor Advisory
- https://mattermost.com/security-updates/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.