Security readout for executives and security teams
Plain-English summary
An exposed Vite development server may return sensitive files that its deny policy should block when specially formed query parameters are added. This could disclose environment files, certificates, credentials, or other project secrets. The issue affects specified Vite 7, Vite 8, and Vite+ versions; production applications without a reachable development server are less likely to be exposed.
Executive priority
Treat internet-accessible affected development servers as urgent because unauthenticated disclosure could expose credentials and enable follow-on compromise. Patch promptly, restrict access immediately, and assess whether secrets were retrieved. Internal-only instances remain high-priority but can be sequenced according to reachability and sensitivity.
Technical view
CVE-2026-39364 is an access-control bypass in Vite's development server. Query handling can bypass server.fs.deny and return blocked files with HTTP 200 responses. The supplied CVSS 4.0 score is 8.2: network-accessible, low complexity, no privileges or user interaction, with high confidentiality impact but no stated integrity or availability impact.
Likely exposure
Highest risk exists where an affected Vite or Vite+ development server is reachable by untrusted users and sensitive files reside within accessible project paths. Internet-facing, shared-network, preview, or improperly promoted development environments deserve immediate review. The source bundle does not establish exposure for ordinary static production builds.
Exploitation context
The bypass uses Vite-supported query processing to circumvent file-deny decisions. The source bundle marks this CVE as absent from KEV and provides no evidence of active exploitation. That does not prove exploitation is absent; review reachable servers and request logs for suspicious access to denied resources.
Researcher notes
Relevant affected ranges are Vite 7.1.0 through 7.3.1, Vite 8.0.0 through 8.0.4, and Vite+ below 0.1.16. The weakness maps to inconsistent interpretation, improper authorization, and external input modification. Evidence supplied establishes confidentiality exposure, not code execution, integrity loss, availability impact, or active exploitation.
Mitigation direction
- Upgrade Vite 7 installations to version 7.3.2 or later.
- Upgrade Vite 8 installations to version 8.0.5 or later.
- Move Vite+ installations outside the affected range below 0.1.16, following vendor guidance.
- Restrict development-server access to trusted networks until remediation is verified.
- Rotate exposed secrets if logs or investigation indicate sensitive-file access.
Validation and detection
- Inventory Vite and Vite+ versions across development, preview, CI, and hosted environments.
- Identify development servers reachable from the internet or other untrusted networks.
- Review server.fs.deny configuration and locate sensitive files within served project paths.
- Inspect access logs for denied-file requests containing raw, import, url, or inline query parameters.
- After upgrading, verify blocked sensitive files no longer return successful responses.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-180: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-472: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-39364 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N——GitHub_MCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N3.93.6redhat-SADPVulnerability scoring details
Base CVSS 4.0 score
8.2HighVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-04-07T20:02:18.458Z: Reported to Red Hat.
- 2026-04-07T19:12:47.577Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/vitejs/vite/security/advisories/GHSA-v2wj-q39q-566rCVE reference, GitHub_M · x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2026-39364CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2456181CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39364.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:24866CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incorrect Behavior Order: Validate Before Canonicalize
Incorrect Behavior Order: Validate Before Canonicalize represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
External Control of Assumed-Immutable Web Parameter
External Control of Assumed-Immutable Web Parameter represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.