EUVD-2026-111245Published

Neko: Authorization bypass in legacy WebRTC input handling

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-116679

Published

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.

Source published: 27 Oct 2026 17:33:35 UTC
Source modified: 28 Oct 2026 16:13:59 UTC
Observed here: 28 Oct 2026 17:46:48 UTC
Source terms: CVE Program Terms of Use

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CVSS 3.1 · 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

euvd · EUVD-2026-111245

Published

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Original publisher date fields

datePublished: Oct 27, 2026, 5:33:35 PM

dateUpdated: Oct 28, 2026, 4:13:59 PM

Source published: Oct 27, 2026, 5:33:35 PM (timezone not stated)
Source modified: Oct 28, 2026, 4:13:59 PM (timezone not stated)
Observed here: 30 Oct 2026 02:00:15 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

nvd · CVE-2026-116679

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-863

Original publisher date fields

published: 2026-10-27T18:17:35.697

lastModified: 2026-10-28T17:18:02.683

Source published: 27 Oct 2026 18:17:35 UTC
Source modified: 28 Oct 2026 17:18:02 UTC
Observed here: 29 Oct 2026 21:50:49 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

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CVSS 3.1 · [email protected] · Secondary · 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

osv · GHSA-5cp7-fp4j-wwcv

Published

### 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](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.

Source published: 27 Oct 2026 21:04:57 UTC
Source modified: 27 Oct 2026 21:15:03 UTC
Observed here: 27 Oct 2026 21:48:52 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

Publisher rating · MODERATE