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Response snapshot Oct 27, 2026, 23:56 UTC

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VulnerabilityCVE-2026-116679

Neko: Authorization bypass in legacy WebRTC input handling

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().

At a glance

Exploited
Not known
Severity
5.4 Medium (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: github.com/m1k1o/neko/server: 0.0.0-20260805142851-395ca1a6f62b. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-5cp7-fp4j-wwcv (opens a new tab)

What happened

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.

Continue reading

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](https://github.com/m1k1o/neko/releases/tag/v3.1.5) by correcting the authorization logic in the legacy WebRTC handler.

Users 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)*

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.

Affected package ranges reported by GitHub: github.com/m1k1o/neko/server: >= 0.0.0-20250401220545-fe94c999c6af, < 0.0.0-20260805142851-395ca1a6f62b

Scores and how they were measured

CVSS base severity

5.4

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-5cp7-fp4j-wwcv (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-5cp7-fp4j-wwcv, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 27). Neko: Authorization bypass in legacy WebRTC input handling (CVE-2026-116679). https://kevwire.com/record/CVE-2026-116679

MLA

"Neko: Authorization bypass in legacy WebRTC input handling (CVE-2026-116679)." KEVWire, 27 Oct. 2026, kevwire.com/record/CVE-2026-116679.

Chicago

KEVWire. "Neko: Authorization bypass in legacy WebRTC input handling (CVE-2026-116679)." Last modified October 27, 2026. https://kevwire.com/record/CVE-2026-116679.

Evidence summary (plain text)

Neko: Authorization bypass in legacy WebRTC input handling (Oct 27, 2026).
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.
CVSS 5.4 (version 3.1; evidence as of Oct 27, 2026; https://github.com/advisories/GHSA-5cp7-fp4j-wwcv).
Sources:
GitHub-reviewed advisory GHSA-5cp7-fp4j-wwcv: https://github.com/advisories/GHSA-5cp7-fp4j-wwcv
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-116679.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 23:40 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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