Vulnerability-Lookup

GHSA-XRRM-6636-87R2

Vulnerability from github – Published: 2026-08-05 12:31 – Updated: 2026-08-05 12:31

Details

In Eclipse Theia versions up to and including 1.73.1, the @theia/filesystem backend exposes HTTP file-download endpoints (GET /file, GET /files/, PUT /files/) that convert a client-supplied URI directly to a filesystem path and stream the file, without confining it to the workspace or any allow-listed root. In browser (non-Electron) deployments the connection token is enforced only on WebSocket upgrades; the HTTP middleware in @theia/core re-issues the cookie and calls next() without rejecting tokenless HTTP requests, so these endpoints are reachable without a valid token. As a result an unauthenticated client can read any file readable by the backend process, including files outside the opened workspace (for example /etc/hosts, SSH keys, or tokens). Electron mode uses a separate ElectronSecurityToken and is not affected via this path.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-61891"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-05T12:18:57Z",
    "severity": "HIGH"
  },
  "details": "In Eclipse Theia versions up to and including 1.73.1, the `@theia/filesystem` backend exposes HTTP file-download endpoints (`GET /file`, `GET /files/`, `PUT /files/`) that convert a client-supplied URI directly to a filesystem path and stream the file, without confining it to the workspace or any allow-listed root. In browser (non-Electron) deployments the connection token is enforced only on WebSocket upgrades; the HTTP middleware in `@theia/core` re-issues the cookie and calls `next()` without rejecting tokenless HTTP requests, so these endpoints are reachable without a valid token. As a result an unauthenticated client can read any file readable by the backend process, including files outside the opened workspace (for example `/etc/hosts`, SSH keys, or tokens). Electron mode uses a separate `ElectronSecurityToken` and is not affected via this path.",
  "id": "GHSA-xrrm-6636-87r2",
  "modified": "2026-08-05T12:31:33Z",
  "published": "2026-08-05T12:31:33Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/eclipse-theia/theia/security/advisories/GHSA-qqc8-9538-25v4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-61891"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/176"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/570"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-61891 (GCVE-0-2026-61891)

Vulnerability from cvelistv5 – Published: 2026-08-05 11:03 – Updated: 2026-08-05 12:35

Summary

In Eclipse Theia versions up to and including 1.73.1, the `@theia/filesystem` backend exposes HTTP file-download endpoints (`GET /file`, `GET /files/`, `PUT /files/`) that convert a client-supplied URI directly to a filesystem path and stream the file, without confining it to the workspace or any allow-listed root. In browser (non-Electron) deployments the connection token is enforced only on WebSocket upgrades; the HTTP middleware in `@theia/core` re-issues the cookie and calls `next()` without rejecting tokenless HTTP requests, so these endpoints are reachable without a valid token. As a result an unauthenticated client can read any file readable by the backend process, including files outside the opened workspace (for example `/etc/hosts`, SSH keys, or tokens). Electron mode uses a separate `ElectronSecurityToken` and is not affected via this path.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

Assigner

eclipse

References

3 references

URL	Tags
https://github.com/eclipse-theia/theia/security/a…
https://gitlab.eclipse.org/security/vulnerability…
https://gitlab.eclipse.org/security/cve-assignmen…

Impacted products

1 product

Vendor	Product	Version
Eclipse Foundation	Eclipse Theia	Affected: 0 , < 1.74.0 (semver)

Credits

Christian Damus (http://github.com/cdamus, https://gitlab.eclipse.org/cdamus)

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-61891",
                "options": [
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                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-05T12:34:58.985421Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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    "cna": {
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          "vendor": "Eclipse Foundation",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-XRRM-6636-87R2

CVE-2026-61891 (GCVE-0-2026-61891)

Tags

Sightings

Nomenclature