Unauthorized View Access to Archived Channel Member Info
Mattermost versions 10.5.x <= 10.5.1, 10.4.x <= 10.4.3, 9.11.x <= 9.11.9 fail to properly enforce the 'Allow users to view/update archived channels' System Console setting, which allows authenticated users to view members and member information of archived channels even when this setting is disabled.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Apr 16, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.3% · 18th percentile
- CWE
- CWE-863
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Report tools
Action score
17
Monitor
Low priority for now.
- CVSS
- 17 / 40 · 4.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
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.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| mattermost | mattermost server | cpe:2.3:a:mattermost:mattermost_server |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- mattermost mattermost server9.11.0 and later · before 9.11.10
- mattermost mattermost server10.4.0 and later · before 10.4.4
- mattermost mattermost server10.5.0 and later · before 10.5.2
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
- 10.6.0, 10.5.2, 10.4.4, 9.11.10not affected
- 10.5.0 and later · up to and including 10.5.1affected · semver
- 10.4.0 and later · up to and including 10.4.3affected · semver
- 9.11.0 and later · up to and including 9.11.9affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | from 10.4.0+incompatible · before 10.4.4+incompatible | 10.4.4+incompatible |
| Go | github.com/mattermost/mattermost-server | from 10.5.0+incompatible · before 10.5.2+incompatible | 10.5.2+incompatible |
| Go | github.com/mattermost/mattermost-server | from 9.11.0+incompatible · before 9.11.10+incompatible | 9.11.10+incompatible |
| Go | github.com/mattermost/mattermost-server/v5 | all versions | — |
| Go | github.com/mattermost/mattermost-server/v6 | all versions | — |
| Go | github.com/mattermost/mattermost/server/v8 | from 10.4.0 · before 10.4.4 | 10.4.4 |
| Go | github.com/mattermost/mattermost/server/v8 | from 10.5.0 · before 10.5.2 | 10.5.2 |
| Go | github.com/mattermost/mattermost/server/v8 | from 9.11.0 · before 9.11.10 | 9.11.10 |
| Go | github.com/mattermost/mattermost/server/v8 | before 8.0.0-20250314142426-c049748b8863 | 8.0.0-20250314142426-c049748b8863 |
| openSUSE:Tumbleweed | govulncheck-vulndb | before 0.0.20250422T181640-1.1 | 0.0.20250422T181640-1.1 |
Same product
mattermost: all recordsOther 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 Endpoint39Monitor
- CVE-2025-12419Account takeover on OAuth/OpenID-enabled servers39Monitor
- CVE-2025-4981Path Traversal Leading to RCE by Any Authenticated Mattermost User39Monitor
- CVE-2023-6458Client side path traversal due to lack of route parameters validation39Monitor
- CVE-2017-18920An issue was discovered in Mattermost Server before 3.6.2.39Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Go:github.com/mattermost/mattermost-server | 10.4.4+incompatible | Package registry (OSV) |
| Go:github.com/mattermost/mattermost-server | 10.5.2+incompatible | Package registry (OSV) |
| Go:github.com/mattermost/mattermost-server | 9.11.10+incompatible | Package registry (OSV) |
| Go:github.com/mattermost/mattermost/server/v8 | 10.4.4 | Package registry (OSV) |
| Go:github.com/mattermost/mattermost/server/v8 | 10.5.2 | Package registry (OSV) |
| Go:github.com/mattermost/mattermost/server/v8 | 8.0.0-20250314142426-c049748b8863 | Package registry (OSV) |
| Go:github.com/mattermost/mattermost/server/v8 | 9.11.10 | Package registry (OSV) |
| opensuse:govulncheck-vulndb | 0.0.20250422T181640-1.1 · openSUSE:Tumbleweed | Package 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.
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 researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- hackit_bharatfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2025-2527426 days apartUnauthorized Command Execution in Archived Channels35Monitor
- CVE-2026-7387422 days apartMattermost group syncable endpoints allow privilege escalation via scheme_admin35Monitor
- CVE-2026-9816488 days apartInsufficient server-side validation of board member role fields permits privilege escalation33Monitor
- CVE-2026-6739422 days apartMattermost: Delegated admins could patch protected default system roles28Monitor
- CVE-2025-3017926 days apartMFA Enforcement Bypass in Search APIs26Monitor
- CVE-2026-2462334 days apartAdmin RCE via Malicious Plugin Upload on CI Test Instances26Monitor
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-863 · Incorrect AuthorizationCVSS 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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.