CVE-2026-33664 Kestra Vulnerable to Stored Cross-Site Scripting via Flow YAML Fields
Attackers can inject malicious JavaScript via flow YAML fields, executing code in victims' browsers to potentially hijack accounts.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-33664?
CVE-2026-33664 is a high-severity cross-site scripting vulnerability in kestra-io kestra, published on 26 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Kestra is an open-source, event-driven orchestration platform Versions up to and including 1.3.3 render user-supplied flow YAML metadata fields — description, inputs[].displayName, inputs[].description — through the Markdown.vue component instantiated with html: true. The resulting HTML is injected into the DOM via Vue's v-html without any sanitization. This allows a flow author to embed arbitrary JavaScript that executes in the browser of any user who views or interacts with the flow. This is distinct from GHSA-r36c-83hm-pc8j / CVE-2026-29082, which covers only FilePreview.vue rendering .md files from execution outputs. The present finding affects different components, different data sources, and requires significantly less user interaction (zero-click for input.displayName). As of time of publication, it is unclear if a patch is available.
Weakness: CWE-79
Which versions are affected by CVE-2026-33664?
It affects 1 product.
Products include Kestra Kestra.
How do I fix CVE-2026-33664?
No fix has been published for CVE-2026-33664 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-33664 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33664 exists.
Other vulnerabilities in kestra-io kestra
- CVE-2026-49869 Kestra OSS OS Command Injection
- CVE-2026-53576 Kestra: Unauthenticated RCE via /configs path-suffix auth-filter bypass
- CVE-2026-34612 Kestra: Remote Code Execution via SQL Injection
- CVE-2026-38428 SQL injection in n/a
- CVE-2026-55069 Kestra BasicAuth Password Stored as SHA-512 Enables Offline Brute-Force Attack
Sources
Also known as GHSA-v2mc-8q95-g7hp.