Mattermost up to 10.11.11/11.2.3/11.3.1/11.4.0/11.4.x unusual condition

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$0-$5k0.11

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Mattermost up to 10.11.11/11.2.3/11.3.1/11.4.0/11.4.x. Affected by this issue is some unknown functionality. Performing a manipulation results in unusual condition. This vulnerability is reported as CVE-2026-20719. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Mattermost up to 10.11.11/11.2.3/11.3.1/11.4.0/11.4.x. This affects an unknown functionality. The manipulation with an unknown input leads to a unusual condition vulnerability. CWE is classifying the issue as CWE-754. The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. This is going to have an impact on availability. The summary by CVE is:

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595

The weakness was disclosed by mk7120. The advisory is shared at mattermost.com. This vulnerability is uniquely identified as CVE-2026-20719 since 02/23/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Neither technical details nor an exploit are publicly available.

Upgrading to version 10.11.12, 11.2.4, 11.3.2, 11.4.1 or 11.5.0 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔒

CNA Base Score: 4.3
CNA Vector (Mattermost): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Unusual condition
CWE: CWE-754
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.11.12/11.2.4/11.3.2/11.4.1/11.5.0

Timelineinfo

02/23/2026 CVE reserved
03/25/2026 +30 days Advisory disclosed
03/25/2026 +0 days VulDB entry created
03/31/2026 +6 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: mk7120
Status: Confirmed

CVE: CVE-2026-20719 (🔒)
GCVE (CVE): GCVE-0-2026-20719
GCVE (VulDB): GCVE-100-353277

Entryinfo

Created: 03/25/2026 18:56
Updated: 03/31/2026 06:24
Changes: 03/25/2026 18:56 (63), 03/31/2026 06:24 (12)
Complete: 🔍
Cache ID: 216:4E1:103

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