CVE-2026-12609 (GCVE-0-2026-12609)
Vulnerability from cvelistv5 – Published: 2026-08-05 10:55 – Updated: 2026-08-05 13:03
VLAI
EPSS
VEX
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.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-05 13:03 UTC
CWE
Assigner
References
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Eclipse Foundation | Eclipse Theia |
Affected:
1.66.0 , < 1.74.0
(semver)
|
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-12609",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-05T13:03:16.183383Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T13:03:23.241Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Eclipse Theia",
"vendor": "Eclipse Foundation",
"versions": [
{
"lessThan": "1.74.0",
"status": "affected",
"version": "1.66.0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "http://github.com/geo-chen"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eIn 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.\u003c/p\u003e"
}
],
"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."
}
],
"impacts": [
{
"capecId": "CAPEC-126",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-126"
}
]
}
],
"metrics": [
{
"cvssV3_1": {
"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"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-22",
"description": "CWE-22",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T10:55:42.736Z",
"orgId": "e51fbebd-6053-4e49-959f-1b94eeb69a2c",
"shortName": "eclipse"
},
"references": [
{
"url": "https://github.com/eclipse-theia/theia/security/advisories/GHSA-qmm6-p8q4-2g48"
},
{
"url": "https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/524"
},
{
"url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/133"
}
],
"source": {
"discovery": "UNKNOWN"
},
"x_generator": {
"engine": "Vulnogram 1.0.4"
}
}
},
"cveMetadata": {
"assignerOrgId": "e51fbebd-6053-4e49-959f-1b94eeb69a2c",
"assignerShortName": "eclipse",
"cveId": "CVE-2026-12609",
"datePublished": "2026-08-05T10:55:42.736Z",
"dateReserved": "2026-06-18T11:33:33.298Z",
"dateUpdated": "2026-08-05T13:03:23.241Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-12609",
"date": "2026-09-24",
"epss": "0.00523",
"percentile": "0.41837"
},
"nvd": {
"cve": {
"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"
}
]
}
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-12609",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-05T13:03:16.183383Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T13:03:19.995Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Eclipse Theia",
"vendor": "Eclipse Foundation",
"versions": [
{
"lessThan": "1.74.0",
"status": "affected",
"version": "1.66.0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "http://github.com/geo-chen"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eIn 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.\u003c/p\u003e"
}
],
"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."
}
],
"impacts": [
{
"capecId": "CAPEC-126",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-126"
}
]
}
],
"metrics": [
{
"cvssV3_1": {
"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"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-22",
"description": "CWE-22",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T10:55:42.736Z",
"orgId": "e51fbebd-6053-4e49-959f-1b94eeb69a2c",
"shortName": "eclipse"
},
"references": [
{
"url": "https://github.com/eclipse-theia/theia/security/advisories/GHSA-qmm6-p8q4-2g48"
},
{
"url": "https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/524"
},
{
"url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/133"
}
],
"source": {
"discovery": "UNKNOWN"
},
"x_generator": {
"engine": "Vulnogram 1.0.4"
}
}
},
"cveMetadata": {
"assignerOrgId": "e51fbebd-6053-4e49-959f-1b94eeb69a2c",
"assignerShortName": "eclipse",
"cveId": "CVE-2026-12609",
"datePublished": "2026-08-05T10:55:42.736Z",
"dateReserved": "2026-06-18T11:33:33.298Z",
"dateUpdated": "2026-08-05T13:03:23.241Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
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.
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…