FKIE_CVE-2026-12609

Vulnerability from fkie_nvd - Published: 2026-08-05 11:16 - Updated: 2026-08-07 20:23
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Summary
In Eclipse Theia versions 1.66.0 and up until including 1.73.1, the `@theia/plugin-ext` backend exposes the `/hostedPlugin/:pluginId/:path(*)` HTTP endpoint, which resolves the requested file path with `path.resolve(localPath, filePath)` without verifying that the resolved path stays within the plugin's directory. An unauthenticated network attacker can send percent-encoded `../` sequences (`%2e%2e%2f`) that decode into the path parameter and escape the plugin directory, allowing arbitrary files readable by the Theia backend process to be retrieved. Plugin IDs are derived deterministically from a plugin's publisher and name, so built-in plugins serve as reliable anchors that require no prior knowledge of the target system.
References
emo@eclipse.orghttps://github.com/eclipse-theia/theia/security/advisories/GHSA-qmm6-p8q4-2g48Broken Link
emo@eclipse.orghttps://gitlab.eclipse.org/security/cve-assignment/-/work_items/133Vendor Advisory
emo@eclipse.orghttps://gitlab.eclipse.org/security/vulnerability-reports/-/issues/524Issue Tracking, Mitigation, Vendor Advisory
Impacted products
Vendor Product Version
eclipse theia *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Eclipse Theia",
          "vendor": "Eclipse Foundation",
          "versions": [
            {
              "lessThan": "1.74.0",
              "status": "affected",
              "version": "1.66.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "emo@eclipse.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:eclipse:theia:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "80478E2F-D9E2-4668-86CF-67913770E0AC",
              "versionEndExcluding": "1.74.0",
              "versionStartIncluding": "1.66.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In Eclipse Theia versions 1.66.0 and up until including 1.73.1, the `@theia/plugin-ext` backend exposes the `/hostedPlugin/:pluginId/:path(*)` HTTP endpoint, which resolves the requested file path with `path.resolve(localPath, filePath)` without verifying that the resolved path stays within the plugin\u0027s directory. An unauthenticated network attacker can send percent-encoded `../` sequences (`%2e%2e%2f`) that decode into the path parameter and escape the plugin directory, allowing arbitrary files readable by the Theia backend process to be retrieved. Plugin IDs are derived deterministically from a plugin\u0027s publisher and name, so built-in plugins serve as reliable anchors that require no prior knowledge of the target system."
    }
  ],
  "id": "CVE-2026-12609",
  "lastModified": "2026-08-07T20:23:46.517",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "emo@eclipse.org",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-12609",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-05T13:03:16.183383Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-05T11:16:24.080",
  "references": [
    {
      "source": "emo@eclipse.org",
      "tags": [
        "Broken Link"
      ],
      "url": "https://github.com/eclipse-theia/theia/security/advisories/GHSA-qmm6-p8q4-2g48"
    },
    {
      "source": "emo@eclipse.org",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/133"
    },
    {
      "source": "emo@eclipse.org",
      "tags": [
        "Issue Tracking",
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/524"
    }
  ],
  "sourceIdentifier": "emo@eclipse.org",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        }
      ],
      "source": "emo@eclipse.org",
      "type": "Secondary"
    }
  ]
}



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