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Full vulnerability report · 2025
CVE-2025-58084High confidence

Mattermost Desktop App crashes when clicking on malformed external URL

Mattermost · Mattermost

3.5LowCVSS 3.1
Recommended action
Scheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityLowOperational priority:Low, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.30% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Mattermost Mattermost and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-34084

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

Mattermost Desktop App versions <= 5.13.0 fail to validate URLs external to the configured Mattermost servers, allowing an attacker on a server the user has configured to crash the user's application by sending the user a malformed URL.

What

Mattermost Desktop App versions <= 5.13.0 fail to validate URLs external to the configured Mattermost servers, allowing an attacker on a server the user has configured to crash the user's application by sending the user a malformed URL.

Why

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.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

Mattermost Desktop App versions <= 5.13.0 fail to validate URLs external to the configured Mattermost servers, allowing an attacker on a server the user has configured to crash the user's application by sending the user a malformed URL.

Why

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.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Validation of Specified Type of Input → disrupt the affected service
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-1287 ↗

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.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.ALowAvailability impact: A successful attack can cause a limited loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkDenial of serviceCWE-1287
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2025-2056Mattermost Desktop: Schwachstellen ermöglichten Denial of Service

Ein Angreifer kann eine Schwachstelle in Mattermost Desktop ausnutzen, um einen Denial of Service zu verursachen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20251015Security Bulletin 15 Oct 2025

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 15 Oct 2025, published on 15 October 2025. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0801Multiples vulnérabilités dans les produits Mattermost

De multiples vulnérabilités ont été découvertes dans les produits Mattermost. Certaines d'entre elles permettent à un attaquant de provoquer un déni de service à distance, une atteinte à la confidentialité des données et un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-017835Mattermost, Inc. の Mattermost Desktop における指定されたタイプの入力に対する不適切な検証に関する脆弱性

Mattermost, Inc. の Mattermost Desktop には、指定されたタイプの入力に対する不適切な検証に関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Mattermost: ≤ 5.13.0
Fixed
Mattermost: 5.13.1
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 13 Oct 2025 · Last source change 14 Oct 2025, 14:28 UTC · CWE-1287 · Improper Validation of Specified Type of Input

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-34084
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2025-34084↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-58084 · cve.blacktree.nl