How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability low.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- Attack vector: Network — reachable from anywhere that can route to the service.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: Low — an ordinary user account is enough.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: None.
- Integrity impact: None.
- Availability impact: Low — limited, and the attacker does not choose what is affected.
Weakness class
CVE-2026-4646 is classified as CWE-1287: Improper Validation of Specified Type of Input. The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type.
Affected software
CVE-2026-4646 is recorded against 3 packages.
- github.com/mattermost/mattermost-plugin-github
- github.com/mattermost/mattermost-server
- mattermost-server (from 11.6.0 up to 11.6.1)
Timeline and source
Published on 7 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.
References
github.com (Advisory)
nvd.nist.gov (Advisory)
github.com (Fix)
mattermost.com (Web)
Other advisories for this package
github.com/mattermost/mattermost-plugin-github has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-1287: Improper Validation of Specified Type of Input) in other software:
