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NVD / CVE Program· CNA Mattermost

CVE-2023-47865: Username and Icon override can be used by members when Hardened Mode is enabled

Noroxi assessment

Priority: Monitor (action score 17/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.41% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: github.com/mattermost/mattermost-server/v6 (Go) 7.8.13; github.com/mattermost/mattermost/server/v8 (Go) 8.1.4.

Low priority for now. Upgrade to github.com/mattermost/mattermost-server/v6 (Go) 7.8.13; github.com/mattermost/mattermost/server/v8 (Go) 8.1.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Mattermost fails to check if hardened mode is enabled when overriding the username and/or the icon when posting a post. If settings allowed integrations to override the username and profile picture when posting, a member could also override the username and icon when making a post even if the Hardened Mode setting was enabled

MediumCVSS 4.3 · v3.1—No exploit Fix available
Published
Nov 27, 2023
Updated
Jun 17, 2026
EPSS
0.4% · 35th percentile

Report tools

JSON

Action score

17

Monitor

Low priority for now.

CVSS
17 / 40 · 4.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CNA vs NVD score

NVD
4.3
CNA · Mattermost
4.3
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
mattermostmattermost

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • mattermost mattermostup to 7.8.12 inclusive
  • mattermost mattermost8.0.0 and later · up to 8.1.3 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Mattermost). Independent of NVD's CPE analysis and usually ahead of it.

  • Mattermost Mattermost

    • 7.8.13, 8.1.4not affected
    • up to and including 8.1.3affected · semver
    • up to and including 7.8.12affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/mattermost/mattermost-server/v6before 7.8.137.8.13
Gogithub.com/mattermost/mattermost/server/v8before 8.1.48.1.4

Same product

mattermost: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-39777Malicious remote can invite itself to an arbitrary local channel
    38Monitor
  • CVE-2023-2193Oauth authorization codes do not expire when deauthorizing an oauth2 app
    36Monitor
  • CVE-2019-20851An issue was discovered in Mattermost Mobile Apps before 1.26.0.
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2023-5968Nov 6, 2023 · Password hash in response body after username update
    19Monitor
  • ← EarlierCVE-2023-5969Nov 6, 2023 · Denial of Service via Link Preview in /api/v4/redirect_location
    21Monitor
  • Later →CVE-2023-35075Nov 27, 2023 · HTML injection via channel autocomplete
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Go:github.com/mattermost/mattermost-server/v67.8.13Package registry (OSV)
Go:github.com/mattermost/mattermost/server/v88.1.4Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2024-39777248 days apartMalicious remote can invite itself to an arbitrary local channel
    38Monitor
  • CVE-2024-8071269 days apartSystem Role with edit access to permissions can elevate themselves to system admin
    28Monitor
  • CVE-2024-6428219 days apartLimited DoS due to permitting creating users with user-defined IDs
    26Monitor
  • CVE-2024-39274248 days apartMalicious remote can add users to arbitrary teams and channels
    26Monitor
  • CVE-2024-36492248 days apartExisting local user overwritten by malicious remote
    25Monitor
  • CVE-2024-39361219 days apartCreating posts with user-defined IDs permitted in CreatePost API
    21Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-284 · Improper Access Control

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records