How severe is CVE-2026-33951?

No CVSS score has been assigned to CVE-2026-33951 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-33951?

CVE-2026-33951 affects the following packages: signalk-server (npm). Ecosystems affected: npm.

How do I fix CVE-2026-33951?

Update signalk-server to 2.24.0-beta.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33951 is resolved across your whole dependency graph.

How do I detect CVE-2026-33951 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for signalk-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-33951 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-33951?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33951 can be triaged on real exposure rather than presence alone.

Is CVE-2026-33951 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-33951 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-33951?

CVE-2026-33951 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 24th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-33951?

CVE-2026-33951 is classified as CWE-284 (CWE-284), Missing Authentication (CWE-306). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-33951 published, and has it been updated?

CVE-2026-33951 was published on April 2, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-33951: signalk-server

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs24th percentile — riskier than 24% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

2other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

signalk-servernpm

3Kdownloads / week

Description

Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.24.0-beta.1, the SignalK Server exposes an unauthenticated HTTP endpoint that allows remote attackers to modify navigation data source priorities. This endpoint, accessible via PUT /signalk/v1/api/sourcePriorities, does not enforce authentication or authorization checks and directly assigns user-controlled input to the server configuration. As a result, attackers can influence which GPS, AIS, or other sensor data sources are trusted by the system. The changes are immediately applied and persisted to disk, allowing the manipulation to survive server restarts. This issue has been patched in version 2.24.0-beta.1.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`signalk-server`	all versions	2.24.0-beta.1`npm install signalk-server@2.24.0-beta.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for signalk-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update signalk-server to 2.24.0-beta.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33951 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33951 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-33951. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.24.0-beta.1, the SignalK Server exposes an unauthenticated HTTP endpoint that allows remote attackers to modify navigation data source priorities. This endpoint, accessible via PUT /signalk/v1/api/sourcePriorities, does not enforce authentication or authorization checks and directly assigns user-controlled input to the server configuration. As a result, attackers can influence which GPS, AIS, or other sensor data sources are trusted by the system. The changes are immediately applied and persisted t

O3 Security · Impact-Aware SCA

Is CVE-2026-33951 in your dependencies?

O3 Security finds CVE-2026-33951 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works

CVE-2026-33951 — signalk-server