Storybook Dev Server Vulnerable to WebSocket Hijacking
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79.
Summary
Storybook is a frontend workshop for building user interface components and pages in isolation. Prior to versions 7.6.23, 8.6.17, 9.1.19, and 10.2.10, the WebSocket functionality in Storybook's dev server, used to create and update stories, is vulnerable to WebSocket hijacking. This vulnerability only affects the Storybook dev server; production builds are not impacted. Exploitation requires a developer to visit a malicious website while their local Storybook dev server is running. Because the WebSocket connection does not validate the origin of incoming connections, a malicious site can silently send WebSocket messages to the local instance without any further user interaction. If the Storybook dev server is intentionally exposed publicly (e.g. for design reviews or stakeholder demos) the risk is higher, as no malicious site visit is required. Any unauthenticated attacker can send WebSocket messages to it directly. The vulnerability affects the WebSocket message handlers for creating and saving stories. Both are vulnerable to injection via unsanitized input in the componentFilePath field, which can be exploited to achieve persistent XSS or Remote Code Execution (RCE). Versions 7.6.23, 8.6.17, 9.1.19, and 10.2.10 contain a fix for the issue.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| storybookjs | storybook | before 7.6.23; 8.1.0 to before 8.6.17; 9.0.0 to before 9.1.19; 10.0.0 to before 10.2.10 | 7.6.23, 8.6.17, 9.1.19, 10.2.10 | Patch available | CNA |
| — | storybook (npm) | 8.1.0 to before 8.6.17 | 8.6.17 | Patch available | GHSA-mjf5-7g4m-gx5w |
| — | storybook (npm) | 8.7.0-alpha.0 to before 9.1.19 | 9.1.19 | Patch available | GHSA-mjf5-7g4m-gx5w |
| — | storybook (npm) | 10.0.0-beta.0 to before 10.2.10 | 10.2.10 | Patch available | GHSA-mjf5-7g4m-gx5w |
- storybook Vendorstorybookjs Affected before 7.6.23; 8.1.0 to before 8.6.17; 9.0.0 to before 9.1.19; 10.0.0 to before 10.2.10 Fixed in 7.6.23, 8.6.17, 9.1.19, 10.2.10 Patch available CNA
- storybook (npm) Vendor— Affected 8.1.0 to before 8.6.17 Fixed in 8.6.17 Patch available GHSA-mjf5-7g4m-gx5w
- storybook (npm) Vendor— Affected 8.7.0-alpha.0 to before 9.1.19 Fixed in 9.1.19 Patch available GHSA-mjf5-7g4m-gx5w
- storybook (npm) Vendor— Affected 10.0.0-beta.0 to before 10.2.10 Fixed in 10.2.10 Patch available GHSA-mjf5-7g4m-gx5w
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:storybook:storybook:*:*:*:*:*:node.js:*:* | before 7.6.23; 8.1.0 to before 8.6.17; 9.0.0 to before 9.1.19; 10.0.0 to before 10.2.10 | Vulnerable | Storybook |
- cpe:2.3:a:storybook:storybook:*:*:*:*:*:node.js:*:* Versions before 7.6.23; 8.1.0 to before 8.6.17; 9.0.0 to before 9.1.19; 10.0.0 to before 10.2.10 Vulnerable ·Storybook
Remediation
- Fix · CNA storybook (storybookjs) Fixed in 7.6.23, 8.6.17, 9.1.19, 10.2.10
- Fix · GHSA-mjf5-7g4m-gx5w storybook (npm) Fixed in 8.6.17 Advisory →
- Fix · GHSA-mjf5-7g4m-gx5w storybook (npm) Fixed in 9.1.19 Advisory →
- Fix · GHSA-mjf5-7g4m-gx5w storybook (npm) Fixed in 10.2.10 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| streams for Apache Kafka 3 | Affected | No fix planned: Will not fix |
Not affected: 3 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- streams for Apache Kafka 2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-27148
- 2026-10-03 Alias added: GHSA-mjf5-7g4m-gx5w
- 2026-10-23 EPSS moved to the 50th–90th percentile
- 2026-10-25 EPSS moved to the below the 50th percentile
- 2026-10-27 EPSS moved to the 50th–90th percentile
References
Patch 4
- https://github.com/storybookjs/storybook/commit/0affdf928bd6fafbadfb1dfe22ce6104805e10e8
- https://github.com/storybookjs/storybook/commit/54689a8add18ea75d628c540f4bc677592a1e685
- https://github.com/storybookjs/storybook/commit/b8cfa77c73940c140acdcd8a06ab1ea913c44761
- https://github.com/storybookjs/storybook/commit/d34085f39c647f5c23c3a3b2d197c18602fcf876
Advisory 2
More storybookjs vulnerabilities
- TI-2026-78906 Storybook dev server exposes WebSocket token to LAN attackers CVSS 4.0HIGH 8.7
- TI-2026-78905 Missing origin checks in Storybook preview allow code injection CVSS 4.0HIGH 8.6
- TI-2026-34698 TeleJSON < 6.0.0 DOM-based XSS via parse() Function CVSS 4.0LOW 2.1
Sources
- CVE-2026-27148 · CVE Program
- CVE-2026-27148 · NVD
- FIRST EPSS
- GHSA-mjf5-7g4m-gx5w · GitHub Advisory Database · CC BY 4.0
- CVE-2026-27148 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences