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NVD / CVE Program· CNA Mattermost

CVE-2026-2463: Unauthorized access to invite ID during team creation

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: 0.17% (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 (Go) 10.11.11, 10.11.11+incompatible, 11.2.3; github.com/mattermost/mattermost/server/v8 (Go) 8.0.0-20260105134819-cc427af41b2a; govulncheck-vulndb (openSUSE:Leap 15.6) 0.0.20260326T203309-150000.1.155.2.

Low priority for now. Upgrade to github.com/mattermost/mattermost-server (Go) 10.11.11, 10.11.11+incompatible, 11.2.3; github.com/mattermost/mattermost/server/v8 (Go) 8.0.0-20260105134819-cc427af41b2a; govulncheck-vulndb (openSUSE:Leap 15.6) 0.0.20260326T203309-150000.1.155.2 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 versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to filter invite IDs based on user permissions, which allows regular users to bypass access control restrictions and register unauthorized accounts via leaked invite IDs during team creation.. Mattermost Advisory ID: MMSA-2025-00565

MediumCVSS 4.3 · v3.1—No exploit Fix available
Published
Mar 16, 2026
Updated
Jun 17, 2026
EPSS
0.1% · 6th 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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Mattermost
4.3
NVD has not scored this yet; the score shown is the CNA’s.

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.

Follow CVE-2026-2463

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 server

Affected versions

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

  • mattermost mattermost server10.11.0 and later · before 10.11.11
  • mattermost mattermost server11.2.0 and later · before 11.2.3
  • mattermost mattermost server11.3.0 and later · before 11.3.1

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

    • 11.4.0, 11.3.1, 11.2.3, 10.11.11not affected
    • 11.3.0 and later · up to and including 11.3.0affected · semver
    • 11.2.0 and later · up to and including 11.2.2affected · semver
    • 10.11.0 and later · up to and including 10.11.10affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Gogithub.com/mattermost/mattermost-serverfrom 10.11.0-rc1 · before 10.11.1110.11.11
Gogithub.com/mattermost/mattermost-serverfrom 10.11.0-rc1+incompatible · before 10.11.11+incompatible10.11.11+incompatible
Gogithub.com/mattermost/mattermost-serverfrom 11.2.0-rc1 · before 11.2.311.2.3
Gogithub.com/mattermost/mattermost-serverfrom 11.2.0-rc1+incompatible · before 11.2.3+incompatible11.2.3+incompatible
Gogithub.com/mattermost/mattermost-serverfrom 11.3.0-rc1 · before 11.3.111.3.1
Gogithub.com/mattermost/mattermost-serverfrom 11.3.0-rc1+incompatible · before 11.3.1+incompatible11.3.1+incompatible
Gogithub.com/mattermost/mattermost-serverbefore 5.3.2-0.20260105134819-cc427af41b2a5.3.2-0.20260105134819-cc427af41b2a
Gogithub.com/mattermost/mattermost-server/v5from 0—
Gogithub.com/mattermost/mattermost-server/v6from 0—
Gogithub.com/mattermost/mattermost/server/v8before 8.0.0-20260105134819-cc427af41b2a8.0.0-20260105134819-cc427af41b2a
openSUSE:Leap 15.6govulncheck-vulndbbefore 0.0.20260326T203309-150000.1.155.20.0.20260326T203309-150000.1.155.2

Same product

mattermost: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-4858Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.
    39Monitor
  • CVE-2025-12421Account Takeover via Code Exchange Endpoint
    39Monitor
  • CVE-2025-12419Account takeover on OAuth/OpenID-enabled servers
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-2461Mar 16, 2026 · Missing authorization check allows unauthorized modification of other users' comments on a board
    17Monitor
  • ← EarlierCVE-2026-2462Mar 16, 2026 · Admin RCE via Malicious Plugin Upload on CI Test Instances
    26Monitor
  • Later →CVE-2026-2578Mar 16, 2026 · Information Disclosure via WebSocket Event When Deleting Unrevealed Burn on Read Posts
    17Monitor

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-server10.11.11Package registry (OSV)
Go:github.com/mattermost/mattermost-server10.11.11+incompatiblePackage registry (OSV)
Go:github.com/mattermost/mattermost-server11.2.3Package registry (OSV)
Go:github.com/mattermost/mattermost-server11.2.3+incompatiblePackage registry (OSV)
Go:github.com/mattermost/mattermost-server11.3.1Package registry (OSV)
Go:github.com/mattermost/mattermost-server11.3.1+incompatiblePackage registry (OSV)
Go:github.com/mattermost/mattermost-server5.3.2-0.20260105134819-cc427af41b2aPackage registry (OSV)
Go:github.com/mattermost/mattermost/server/v88.0.0-20260105134819-cc427af41b2aPackage registry (OSV)
opensuse:govulncheck-vulndb0.0.20260326T203309-150000.1.155.2 · openSUSE:Leap 15.6Package 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-2025-58073151 days apartArbitrary Mattermost Team can be joined by manipulating the OAuth state
    32Monitor
  • CVE-2025-58075151 days apartArbitrary Mattermost Team can be joined by manipulating the SAML RelayState
    32Monitor
  • CVE-2026-8821182 days apartPlaybooks run owner channel membership permission bypass
    28Monitor
  • CVE-2026-311763 days apartInstance and webhook GitLab plugin commands were able to be run by non-admin users
    26Monitor
  • CVE-2026-516363 days apartMissing authorization check in AI message rewrite endpoint allows access to private thread content
    26Monitor
  • CVE-2025-9076182 days apartMattermost Server exposes sensitive user credentials during shared channel membership synchronization
    26Monitor

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

Weakness class (CWE)

CWE-862 · Missing Authorization

CVSS vector

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

nvd-secondary

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