Security readout for executives and security teams
Plain-English summary
A remotely reachable Vite development server may disclose files its deny policy should protect, including environment or certificate files. An unauthenticated requester can trigger the flaw using specially formed query parameters. Exposure could reveal secrets and enable follow-on compromise, although the supplied sources do not establish active exploitation.
Executive priority
Prioritize within the normal high-severity remediation window, accelerating internet-facing or shared-network development servers. Immediately restrict reachability where upgrades cannot be completed. Treat confirmed sensitive-file disclosure as a potential secret exposure requiring incident review and credential rotation.
Technical view
CVE-2026-39364 is a query-handling bypass of Vite's `server.fs.deny` controls. Affected dev servers may return denied files with HTTP 200 when certain transform-related query parameters are supplied. Vite 7.1.0 through 7.3.1, 8.0.0 through 8.0.4, and Vite Plus before 0.1.16 are affected.
Likely exposure
Risk is highest where an affected Vite dev server is reachable from untrusted networks and sensitive files exist within accessible filesystem scope. Production sites serving only built static assets are not identified as affected. Internal dev servers still matter if reachable by compromised devices or other untrusted network users.
Exploitation context
The CVSS 4.0 score is 8.2: network-accessible, low complexity, no privileges, and no user interaction, with high confidentiality impact. The vector includes an attack requirement, so exposure depends on deployment and file availability. The CVE is not listed as KEV in the supplied bundle, and no cited evidence establishes active exploitation.
Researcher notes
The reported behavior aligns with improper canonicalization and authorization handling represented by CWE-180, CWE-284, and CWE-472. Validation should remain non-destructive and avoid collecting secret contents. The supplied evidence identifies confidentiality impact but does not document integrity or availability impact, public exploit availability, observed attacks, or every deployment condition required.
Mitigation direction
- Upgrade Vite 7.x to 7.3.2 or later.
- Upgrade Vite 8.x to 8.0.5 or later.
- Upgrade Vite Plus to 0.1.16 or later, following vendor guidance.
- Prevent development servers from being reachable by untrusted networks.
- Rotate exposed secrets if investigation indicates protected files may have been retrieved.
Validation and detection
- Inventory Vite and Vite Plus versions across development, CI, preview, and container environments.
- Confirm no affected development server is publicly or broadly internally reachable.
- Review server logs for unusual query-driven raw, import, URL, or inline file requests.
- Verify upgraded servers enforce `server.fs.deny` without exposing sensitive file contents.
- Identify potentially exposed credentials or certificates and assess whether rotation is required.
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.