Vulnerability-Lookup

GHSA-5CP7-FP4J-WWCV

Vulnerability from github – Published: 2026-10-27 21:04 – Updated: 2026-10-27 21:04

Summary

Neko: Authorization bypass in legacy WebRTC input handling

Details

Impact

When legacy mode is enabled and session.implicit_hosting is enabled, the legacy WebRTC data channel incorrectly authorizes input events due to a logic error in LegacyIsHost().

As a result, an authenticated room member may be able to send mouse and keyboard input through the legacy WebRTC control channel even when controls are locked or the member would otherwise not be authorized through the modern control API.

The issue affects only the legacy WebRTC input path. The modern HTTP/WebSocket control path correctly enforces authorization checks and is not affected.

To exploit this issue, an attacker must:

Be authenticated as a room member.
Successfully establish a WebRTC connection.
Access a deployment using the legacy WebRTC input handler.

No unauthenticated access or privilege escalation outside the application is possible.

Patches

The issue has been fixed in v3.1.5 by correcting the authorization logic in the legacy WebRTC handler.

Users should upgrade to v3.1.5 or later. Fix: 395ca1a

Workarounds

Users who cannot immediately upgrade can mitigate the issue by one of the following:

Disable legacy mode if it is not required.
Disable implicit hosting (session.implicit_hosting=false).
Restrict access to trusted authenticated users.

Credits

Thanks to @KasperBuilds for responsibly disclosing this vulnerability and reaching out directly. This contribution helped strengthen the project, and the whole community benefits from it.

Severity

5.4 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/m1k1o/neko/server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-20250401220545-fe94c999c6af"
            },
            {
              "fixed": "0.0.0-20260805142851-395ca1a6f62b"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-116679"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-27T21:04:57Z",
    "nvd_published_at": "2026-10-27T18:17:35Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nWhen legacy mode is enabled and `session.implicit_hosting` is enabled, the legacy WebRTC data channel incorrectly authorizes input events due to a logic error in `LegacyIsHost()`.\n\nAs a result, an authenticated room member may be able to send mouse and keyboard input through the legacy WebRTC control channel even when controls are locked or the member would otherwise not be authorized through the modern control API.\n\nThe issue affects only the legacy WebRTC input path. The modern HTTP/WebSocket control path correctly enforces authorization checks and is not affected.\n\nTo exploit this issue, an attacker must:\n\n* Be authenticated as a room member.\n* Successfully establish a WebRTC connection.\n* Access a deployment using the legacy WebRTC input handler.\n\nNo unauthenticated access or privilege escalation outside the application is possible.\n\n### Patches\n\nThe issue has been fixed in **[v3.1.5](https://github.com/m1k1o/neko/releases/tag/v3.1.5)** by correcting the authorization logic in the legacy WebRTC handler.\n\nUsers should upgrade to **[v3.1.5](https://github.com/m1k1o/neko/releases/tag/v3.1.5)** or later. Fix: *[395ca1a](https://github.com/m1k1o/neko/commit/395ca1a6f62b7b0e270e654d366a2d57b8042efd)*\n\n### Workarounds\n\nUsers who cannot immediately upgrade can mitigate the issue by one of the following:\n\n* Disable legacy mode if it is not required.\n* Disable implicit hosting (`session.implicit_hosting=false`).\n* Restrict access to trusted authenticated users.\n\n### Credits\n\nThanks to @KasperBuilds for responsibly disclosing this vulnerability and reaching out directly. This contribution helped strengthen the project, and the whole community benefits from it.",
  "id": "GHSA-5cp7-fp4j-wwcv",
  "modified": "2026-10-27T21:04:57Z",
  "published": "2026-10-27T21:04:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/m1k1o/neko/security/advisories/GHSA-5cp7-fp4j-wwcv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-116679"
    },
    {
      "type": "WEB",
      "url": "https://github.com/m1k1o/neko/pull/675"
    },
    {
      "type": "WEB",
      "url": "https://github.com/m1k1o/neko/commit/395ca1a6f62b7b0e270e654d366a2d57b8042efd"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/m1k1o/neko"
    },
    {
      "type": "WEB",
      "url": "https://github.com/m1k1o/neko/releases/tag/v3.1.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Neko: Authorization bypass in legacy WebRTC input handling"
}

CVE-2026-116679 (GCVE-0-2026-116679)

Vulnerability from cvelistv5 – Published: 2026-10-27 17:33 – Updated: 2026-10-28 16:13

Title

Neko: Authorization bypass in legacy WebRTC input handling

Summary

Neko is a a self-hosted virtual browser that runs in Docker and uses WebRTC. From version 3.0.0 until 3.1.5, Neko deployments with legacy mode and session.implicit_hosting enabled incorrectly authorize legacy WebRTC data-channel input because LegacyIsHost() evaluates host status incorrectly. An authenticated room member who establishes a WebRTC connection can send mouse and keyboard events through the legacy control channel while controls are locked or the member is otherwise unauthorized by the modern control API. This issue is fixed in version 3.1.5.

Severity

5.4 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-28 14:34 UTC

CWE

CWE-863 - Incorrect Authorization

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7926 records in the last 180 days details

References

4 references

URL	Tags
https://github.com/m1k1o/neko/security/advisories…	x_refsource_CONFIRM
https://github.com/m1k1o/neko/pull/675	x_refsource_MISC
https://github.com/m1k1o/neko/commit/395ca1a6f62b…	x_refsource_MISC
https://github.com/m1k1o/neko/releases/tag/v3.1.5	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
m1k1o	neko	Affected: >= 3.0.0, < 3.1.5

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-116679",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-28T14:34:30.608545Z",
                "version": "2.0.3"
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              "type": "ssvc"
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        "providerMetadata": {
          "dateUpdated": "2026-10-28T16:13:59.494Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
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          "product": "neko",
          "vendor": "m1k1o",
          "versions": [
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              "status": "affected",
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            }
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          "value": "Neko is a a self-hosted virtual browser that runs in Docker and uses WebRTC. From version 3.0.0 until 3.1.5, Neko deployments with legacy mode and session.implicit_hosting enabled incorrectly authorize legacy WebRTC data-channel input because LegacyIsHost() evaluates host status incorrectly. An authenticated room member who establishes a WebRTC connection can send mouse and keyboard events through the legacy control channel while controls are locked or the member is otherwise unauthorized by the modern control API. This issue is fixed in version 3.1.5."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.4,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L",
            "version": "3.1"
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      "problemTypes": [
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          "descriptions": [
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              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
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      "providerMetadata": {
        "dateUpdated": "2026-10-27T17:33:35.883Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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          "tags": [
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          "url": "https://github.com/m1k1o/neko/security/advisories/GHSA-5cp7-fp4j-wwcv"
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          "name": "https://github.com/m1k1o/neko/pull/675",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/m1k1o/neko/pull/675"
        },
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  "cveMetadata": {
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    "datePublished": "2026-10-27T17:33:35.883Z",
    "dateReserved": "2026-10-26T20:00:59.829Z",
    "dateUpdated": "2026-10-28T16:13:59.494Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Vulnerability timeline

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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.
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