OpenC3 COSMOS up to 7.2.x Button Widget ButtonWidget.vue cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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4.9$0-$5k0.00+

Summaryinfo

A vulnerability categorized as problematic has been discovered in OpenC3 COSMOS up to 7.2.x. The impacted element is an unknown function of the file openc3-cosmos-init/plugins/packages/openc3-vue-common/src/widgets/ButtonWidget.vue of the component Button Widget. Such manipulation leads to cross site scripting. This vulnerability is referenced as CVE-2026-77394. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenC3 COSMOS up to 7.2.x. It has been rated as problematic. Affected by this issue is an unknown functionality of the file openc3-cosmos-init/plugins/packages/openc3-vue-common/src/widgets/ButtonWidget.vue of the component Button Widget. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. From 5.0.6 until 7.3.0, an authenticated actor with system_set permission can store a shared screen through POST /openc3-api/screen whose BUTTON widget action is evaluated by openc3-cosmos-init/plugins/packages/openc3-vue-common/src/widgets/ButtonWidget.vue in another operator's browser session when the button is activated. The stored script runs in the COSMOS origin and can read localStorage.openc3Token, allowing theft of the victim's bearer token, account takeover, and actions with the victim's privileges. The permissive content security policy contributes to execution but is not the primary root cause. This issue is fixed in version 7.3.0.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-77394 since 08/20/2026. The exploitation is known to be easy. The attack may be launched remotely. The exploitation requires an enhanced level of successful authentication. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

Upgrading to version 7.3.0 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 2.4
VulDB Temp Score: 2.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.6
CNA Vector (GitHub_M): 🔒

CVSSv2info

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

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
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: COSMOS 7.3.0

Timelineinfo

08/20/2026 CVE reserved
09/23/2026 +34 days Advisory disclosed
09/23/2026 +0 days VulDB entry created
09/23/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-77394 (🔒)
GCVE (CVE): GCVE-0-2026-77394
GCVE (VulDB): GCVE-100-409130

Entryinfo

Created: 09/23/2026 21:16
Changes: 09/23/2026 21:16 (65)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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