Vite is a frontend tooling framework for JavaScript. From 8.2.0 until 8.2.4 and 8.3.3, the first 4 bytes of files outside of server.fs setting can be returned to the browser by a request containing ?vite-wasm-instance. Requests containing the ?vite-wasm-instance query are handled by the internal Wasm plugin's load hook. The hook removes the query and reads the resulting path directly from disk, but the server.fs checks were not applied. After reading the file, Vite attempts to parse it as WebAssembly. When that parse fails, Node and deno throws an error that contains the first 4 bytes of the file. This vulnerability is fixed in 8.2.4 and 8.3.3.
CVE-2026-112947
MEDIUMPre-NVD 6.36.3Trending — 3 sources updated this week
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (35th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Triggered by: Headline CVSS from a secondary CVSS source
Sources: a secondary CVSS source
6.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.3Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 6.3
- EG Score
- 6.3MEDIUMlow confidence
- EG Risk
- 28EG Risk 28/100
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)Severity63% × 45%Impact severity (EG Severity): CVSS 6.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0% × 40%No KEV listing, EG-KEV tier or EPSS when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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
- 0.4%
- EPSS %ILE
- 35th
- 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 (6.3): severity, escalated by confirmed exploitation. This CVE's 6.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 6.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.4% within 30 daysSource: FIRST EPSS. 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (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
October 20, 2026
Last Modified
October 21, 2026
Advisory Details (4)
Auto-updated Oct 20, 2026🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit.
GitHub commit Patch Available
commit ba8b7ab43b4a (vitejs/vite)
Patch available: vitejs/vite v8.3.3 (contains commit ba8b7ab43b4a)
https://github.com/vitejs/vite/commit/ba8b7ab43b4afa5d0292ab4b6e3a7b5033cc9c73GitHub commit Patch Available
commit b6c6d2fb3f85 (vitejs/vite)
Patch available: vitejs/vite v8.2.4 (contains commit b6c6d2fb3f85)
https://github.com/vitejs/vite/commit/b6c6d2fb3f853aab4092dc25f0d6816a96c23dffGitHub pull request Patch Available
fix(server): check `fs.serve` for `?vite-wasm-instance`
Patch available: vitejs/vite v8.3.3 (PR #23655 merged 2026-10-06)
https://github.com/vitejs/vite/pull/23655GitHub advisoryMentions a patch (unverified)🟡 PoC Available
First 4 bytes of files outside of `server.fs` setting is exposed by `?vite-wasm-instance` · Advisory · vitejs/vite · GitHub
https://github.com/vitejs/vite/security/advisories/GHSA-vfpm-58rq-9qcgVendor Advisories for CVE-2026-112947(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× 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.
- 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-21 16:31 UTCEG score recompute
- 2026-10-21 16:01 UTCEG score recompute
- 2026-10-20 16:28 UTCEG score recompute
- 2026-10-20 15:24 UTCEG score recomputeFirst assessed: 6.3 MEDIUM
- 2026-10-20 15:21 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-112947?
CVE-2026-112947 is a medium-severity vulnerability; its CVE record was published on October 20, 2026. Vite is a frontend tooling framework for JavaScript. From 8.2.0 until 8.2.4 and 8.3.3, the first 4 bytes of files outside of server.fs setting can be returned to the browser by a request containing ?vite-wasm-instance. Requests containing the ?vite-wasm-instance query are handled by the internal…
When was the CVE record for CVE-2026-112947 published?
The CVE record for CVE-2026-112947 was published on October 20, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 21, 2026; the record at its source may have been updated since.
Is CVE-2026-112947 actively exploited?
CVE-2026-112947 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-112947?
CVE-2026-112947 has a CVSS base score of 6.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-112947?
A fix for CVE-2026-112947 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-112947 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-112947
Is Your Infrastructure Affected by CVE-2026-112947?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.