CVE-2026-61891Public exploitNetwork attack vector

Unauthenticated file read via uncontained download paths

Published Aug 5, 2026 · Updated Aug 5, 2026

Path traversal in Eclipse Theia 1.73.1 and earlier allows remote attackers to read backend-accessible files through HTTP download endpoints. The @theia/filesystem handlers pass client-supplied file URIs to FileUri.fsPath and stream the resulting absolute paths without workspace or root containment. Browser-mode HTTP middleware does not reject tokenless requests, exposing any file readable by the backend process; Electron mode is unaffected.

CVSS severity7.5
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Eclipse Theia 1.73.1 and earlier allows remote attackers to read backend-accessible files through HTTP download endpoints. The @theia/filesystem handlers pass client-supplied file URIs to FileUri.fsPath and stream the resulting absolute paths without workspace or root containment. Browser-mode HTTP middleware does not reject tokenless requests, exposing any file readable by the backend process; Electron mode is unaffected.

The record

CVE
CVE-2026-61891
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
The Eclipse Foundation
Product
Eclipse Theia
Classifications
CWE-306, CWE-22, CWE-200, CWE-36, CAPEC-597, CAPEC-126, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.74.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Eclipse Foundation · Eclipse Theiaversion=0 <1.74.0

Published CVSS scores

7.5Eclipse FoundationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-36Absolute Path Traversal
CAPEC-597Absolute Path Traversal
CAPEC-126Path Traversal
T1005Data from Local System

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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