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.
CVE-2026-27148
“—” beside the score: it is equal to NVD's CVSS score.
This critical-severity CVE scores 9.6 under NVD CVSS v3. EPSS exploit probability: 0.6% (50th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-8750 (ENISA EUVD) · GHSA-mjf5-7g4m-gx5w (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 9.6
- EG Score
- 9.6CRITICALmedium confidence
- EG Risk
- 43EG Risk 43/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity96% × 45%Impact severity (EG Severity): CVSS 9.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.6% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.6%
- EPSS %ILE
- 50th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.6): severity, escalated by confirmed exploitation. This CVE's 9.6 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.6 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
February 25, 2026
Last Modified
July 15, 2026
Advisory Details (10)
Auto-updated Oct 7, 2026CVE-2026-27148 - Red Hat Customer Portal
Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a
https://access.redhat.com/security/cve/CVE-2026-27148Storybook dev server vulnerable to WebSocket hijacking · Advisory · storybookjs/storybook · GitHub
https://github.com/storybookjs/storybook/security/advisories/GHSA-mjf5-7g4m-gx5wv9.1.19
Patch available: storybookjs/storybook v9.1.19
https://github.com/storybookjs/storybook/releases/tag/v9.1.19v8.6.17
Patch available: storybookjs/storybook v8.6.17
https://github.com/storybookjs/storybook/releases/tag/v8.6.17v7.6.23
Patch available: storybookjs/storybook v7.6.23
https://github.com/storybookjs/storybook/releases/tag/v7.6.23v10.2.10
Patch available: storybookjs/storybook v10.2.10
https://github.com/storybookjs/storybook/releases/tag/v10.2.10commit d34085f39c64 (storybookjs/storybook)
Fix landed in storybookjs/storybook commit d34085f39c64 — awaiting tagged release
https://github.com/storybookjs/storybook/commit/d34085f39c647f5c23c3a3b2d197c18602fcf876commit b8cfa77c7394 (storybookjs/storybook)
Fix landed in storybookjs/storybook commit b8cfa77c7394 — awaiting tagged release
https://github.com/storybookjs/storybook/commit/b8cfa77c73940c140acdcd8a06ab1ea913c44761commit 54689a8add18 (storybookjs/storybook)
Fix landed in storybookjs/storybook commit 54689a8add18 — awaiting tagged release
https://github.com/storybookjs/storybook/commit/54689a8add18ea75d628c540f4bc677592a1e685commit 0affdf928bd6 (storybookjs/storybook)
Fix landed in storybookjs/storybook commit 0affdf928bd6 — awaiting tagged release
https://github.com/storybookjs/storybook/commit/0affdf928bd6fafbadfb1dfe22ce6104805e10e8Patch Availability(3)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| npm | storybook @ 8.6.17 (fixes >= 8.1.0, < 8.6.17) | — | ghsa |
| npm | storybook @ 9.1.19 (fixes >= 8.7.0-alpha.0, < 9.1.19) | — | ghsa |
| npm | storybook @ 10.2.10 (fixes >= 10.0.0-beta.0, < 10.2.10) | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| storybook | — |
| — |
Weakness Classification(4)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 15× in last 7d / 57× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 97 of 171 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 74 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-11-01 21:03 UTCEG score recompute
- 2026-11-01 21:03 UTCGHSA enrichmentGHSA-mjf5-7g4m-gx5w · GitHub severity HIGH
- 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-11-01 07:56 UTCGHSA enrichmentGHSA-mjf5-7g4m-gx5w · GitHub severity HIGH
- 2026-10-31 20:22 UTCEG score recompute
- 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-30 19:43 UTCEG score recompute
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-29 19:02 UTCEG score recompute
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-28 18:22 UTCEG score recompute
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-27 17:37 UTCEG score recompute
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-26 16:57 UTCEG score recompute
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-25 14:39 UTCEG score recompute
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-24 15:19 UTCEG score recompute
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-23 14:39 UTCEG score recompute
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-22 13:59 UTCEG score recompute
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- 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-21 13:18 UTCEG score recompute
- 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-20 12:32 UTCEG score recompute
- 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-19 11:49 UTCEG score recompute
- 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-18 03:51 UTCEG score recompute
- 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-17 08:28 UTCEG score recompute
- 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-16 07:47 UTCEG score recompute
- 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-15 06:47 UTCEG score recompute
- 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-14 02:31 UTCEG score recompute
- 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-12 22:45 UTCEG score recompute
- 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-12 16:17 UTCEG score recompute
- 2026-10-11 20:00 UTCEG score recompute
- 2026-10-11 17:13 UTCEG score recompute
- 2026-10-11 14:44 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-09 13:58 UTCOSV refresh
- 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-09-19 21:30 UTCOSV refresh
- 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-09-01 00:34 UTCOSV refresh
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-08-14 08:59 UTCEG score recompute
Related CVEs(same product + same CWE)
Same product
3 shownnpm:storybook
Frequently asked(5)
What is CVE-2026-27148?
When was the CVE record for CVE-2026-27148 published?
Is CVE-2026-27148 actively exploited?
What is the CVSS score of CVE-2026-27148?
How do I remediate CVE-2026-27148?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-27148
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