CVE-2024-2435: Stored XSS in Timeline View

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-02 · updated 2026-06-17
Weakness: CWE-79

Description

For an attacker with pre-existing access to send a signal to a workflow, the attacker can make the signal name a script that executes when a victim views that signal. The XSS is in the timeline page displaying the workflow execution details of the workflow that was sent the crafted signal. Access to send a signal to a workflow is determined by how you configured the authorizer on your server. This includes any entity with permission to directly call SignalWorkflowExecution or SignalWithStartWorkflowExecution, or any entity can deploy a worker that has access to call workflow progress APIs (specifically RespondWorkflowTaskCompleted).

Affected products

Temporal OSS ui-server: from 2.16.2 before 2.25.0 — fixed in 2.25.0

How to fix

Upgrade to a fixed version: Temporal OSS ui-server 2.25.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-2435 or the next vulnerability affects your stack