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CVE Record

CVE-2026-63188: logto-tunnel serves files outside --experience-path via path traversal

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 0.3.9, the Logto Tunnel npm package enabled createStaticFileProxy from packages/tunnel/src/commands/tunnel/index.ts and passed request.url from static asset requests through packages/tunnel/src/commands/tunnel/utils.ts using path.join(staticPath, request.url) and then fs.open(requestPath, "r") without URL normalization or a containment check. When --experience-path was enabled and the tunnel port was reachable, an unauthenticated requester could send a path containing ../ to createStaticFileProxy and read files outside the configured static directory that were readable by the logto-tunnel process. The service used server.listen(port), which could expose the tunnel to other hosts depending on the platform and deployment. This issue is fixed in version 0.3.9.

HighCVSS 8.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A flaw in Logto Tunnel can let an unauthenticated network user read files outside the intended static directory. Exposure requires a vulnerable version, the --experience-path option, and a reachable tunnel port. Files are limited to those readable by the tunnel process, but may include sensitive configuration or credentials.

Executive priority

Prioritize remediation for internet-facing or broadly reachable tunnel instances immediately, especially where the process can read secrets or sensitive application files. Other vulnerable installations should be upgraded promptly after confirming configuration and network exposure. No active exploitation is established by the supplied evidence.

Technical view

Before @logto/tunnel 0.3.9, static asset requests were combined with the configured directory using path.join and opened without URL normalization or directory-containment validation. Directory traversal could therefore escape the configured experience path. The issue is CWE-22 and scored CVSS 4.0 8.7, reflecting network-accessible, low-complexity confidentiality impact without authentication or user interaction.

Likely exposure

Highest risk applies to Logto Tunnel versions earlier than 0.3.9 where --experience-path is enabled and the listening port is reachable by untrusted hosts. Actual data exposure depends on the operating-system permissions of the tunnel process. Deployments without that option or without network reachability are not described as exploitable by the supplied sources.

Exploitation context

The vulnerability is remotely reachable and requires neither authentication nor user interaction under the stated deployment conditions. The supplied record says KEV is false and provides no evidence of active exploitation. Public disclosure includes the vulnerable implementation, corrective change, and release, which may increase attacker awareness.

Researcher notes

The security boundary failure is insufficient canonicalization and containment enforcement before fs.open. Impact is read-only according to the supplied record: confidentiality is high, while integrity and availability are unaffected. Scope should be assessed per process identity, filesystem permissions, --experience-path usage, and listener reachability. Version 0.3.9 is the documented fix.

Mitigation direction

  • Upgrade @logto/tunnel to version 0.3.9 or later.
  • Until upgraded, disable --experience-path where operationally feasible.
  • Restrict the tunnel port to trusted hosts and networks.
  • Limit the tunnel process account to only necessary file permissions.
  • Review the vendor advisory and release notes for deployment-specific guidance.

Validation and detection

  • Inventory deployed @logto/tunnel versions and identify installations below 0.3.9.
  • Confirm whether each vulnerable instance enables --experience-path.
  • Determine whether tunnel ports are reachable from untrusted networks.
  • Review service-account permissions and identify sensitive readable files.
  • After upgrading, verify the installed package resolves to 0.3.9 or later.
  • Review access logs for unusual static-file requests, without treating absence as proof of safety.
Prepared
Confidence
high
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · medium confidence lookup

CWE-22: File access and web shell behavior lookup

File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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.

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description · low confidence lookup

File access behavior lookup

The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-63188 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.7 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Official CVE source material

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.

1CVSS vectors
3Timeline events
0ADP providers
5Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
8.7CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N——GitHub_M

Vulnerability scoring details

Base CVSS 4.0 score

8.7High
CVSS 4.0 vector shape for CVE-2026-63188Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
logto-iologto< 0.3.9Listed
Weakness

CWE details

CWE-22

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-22 · source CWE mapping

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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