CVE-2026-27148Network attack vector

Code execution via origin-unchecked WebSocket messages

Published Feb 25, 2026 · Updated Feb 25, 2026

WebSocket hijacking in affected Storybook releases allows remote attackers to inject code into story source files through the dev server. The create and save message handlers accept componentFilePath from WebSocket clients without origin validation or input sanitization, then write attacker-controlled payloads into story files. A local attack requires a developer to visit a malicious site while the server runs; a publicly exposed server is directly reachable, and server-side code execution requires non-default portable stories in JSDOM.

CVSS severity8.9
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

WebSocket hijacking in affected Storybook releases allows remote attackers to inject code into story source files through the dev server. The create and save message handlers accept componentFilePath from WebSocket clients without origin validation or input sanitization, then write attacker-controlled payloads into story files. A local attack requires a developer to visit a malicious site while the server runs; a publicly exposed server is directly reachable, and server-side code execution requires non-default portable stories in JSDOM.

The record

CVE
CVE-2026-27148
Published
Feb 25, 2026
Updated
Feb 25, 2026
Vendor
Storybook
Product
Storybook
Classifications
CWE-1385, CWE-346, CWE-79, CWE-74, T1190, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 10.0.0, < 10.2.10
  2. Affected versionversion=< 7.6.23
  3. Affected versionversion=>= 8.1.0, < 8.6.17
  4. Affected versionversion=>= 9.0.0, < 9.1.19

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Storybook · Storybookversion=>= 10.0.0, < 10.2.10; version=< 7.6.23; version=>= 8.1.0, < 8.6.17; version=>= 9.0.0, < 9.1.19

Published CVSS scores

9.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
8.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
8.8Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1385Missing Origin Validation in WebSockets
CWE-346Origin Validation Error
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1190Exploit Public-Facing Application
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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