How severe is CVE-2026-50166?

No CVSS score has been assigned to CVE-2026-50166 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-50166?

CVE-2026-50166 affects the following packages: github.com/kumahq/kuma/v2 (Go), github.com/kumahq/kuma/v2 (Go), github.com/kumahq/kuma/v2 (Go), github.com/kumahq/kuma/v2 (Go), github.com/kumahq/kuma/v2 (Go), github.com/kumahq/kuma (Go). Ecosystems affected: Go.

How do I fix CVE-2026-50166?

Update github.com/kumahq/kuma/v2 to 2.7.26 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50166 is resolved across your whole dependency graph.

How do I detect CVE-2026-50166 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/kumahq/kuma/v2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-50166 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.

Is CVE-2026-50166 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-50166 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-2026-50166?

CVE-2026-50166 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 19th 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-2026-50166?

CVE-2026-50166 is classified as CWE-295 (CWE-295). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-50166 published, and has it been updated?

CVE-2026-50166 was published on September 15, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2026-50166 — kuma

Fix: kumahq/kuma@2d0fb38

CVE-2026-50166 is a CWE-295 vulnerability in github.com/kumahq/kuma/v2. A fix is available for github.com/kumahq/kuma/v2 — see the affected versions and patch details below.

Kuma: kumactl connects to control plane without verifying TLS certificate when no CA is configured

Also known asCVE-2026-18678 GHSA-v95x-xhq5-4929GO-2026-6010

Published

Sep 15, 2026

Updated

Oct 21, 2026

Affected

6 pkgs

Patched

5 / 6

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-50166.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs19th percentile — riskier than 19% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

6 pkgs affected

🐹github.com/kumahq/kuma/v2🐹github.com/kumahq/kuma/v2🐹github.com/kumahq/kuma/v2🐹github.com/kumahq/kuma/v2🐹github.com/kumahq/kuma/v2🐹github.com/kumahq/kuma

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

When an operator adds an HTTPS control plane profile to kumactl without providing a CA certificate, kumactl disables TLS verification and sends API tokens over the unverified connection

Impact

An attacker on the network path between the operator and the control plane can intercept user or admin API tokens and then act against the control plane as that user

Affected configurations

kumactl profiles manually added against an HTTPS control plane endpoint without --ca-cert-file

Not affected

The default local profile, which uses plain HTTP

Workarounds

When adding an HTTPS control plane profile to kumactl, always pass --ca-cert-file pointing at the control plane's serving CA. Alternatively, terminate the control plane behind a publicly trusted certificate; the patched releases will verify successfully against the operating system trust store with no further configuration

Resources

Fix: https://github.com/kumahq/kuma/pull/16777

Affected Packages

6 total 5 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/kumahq/kuma/v2`	all versions	2.7.26`go get github.com/kumahq/kuma/v2@v2.7.26`
🐹Go	`github.com/kumahq/kuma/v2`	≥ 2.8.0&&< 2.9.16	2.9.16`go get github.com/kumahq/kuma/v2@v2.9.16`
🐹Go	`github.com/kumahq/kuma/v2`	≥ 2.10.0&&< 2.11.14	2.11.14`go get github.com/kumahq/kuma/v2@v2.11.14`
🐹Go	`github.com/kumahq/kuma/v2`	≥ 2.12.0&&< 2.12.11	2.12.11`go get github.com/kumahq/kuma/v2@v2.12.11`
🐹Go	`github.com/kumahq/kuma/v2`	≥ 2.13.0&&< 2.13.7	2.13.7`go get github.com/kumahq/kuma/v2@v2.13.7`
🐹Go	`github.com/kumahq/kuma`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/kumahq/kuma/v2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/kumahq/kuma/v2 to 2.7.26 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50166 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.

Frequently Asked Questions

When an operator adds an HTTPS control plane profile to `kumactl` without providing a CA certificate, `kumactl` disables TLS verification and sends API tokens over the unverified connection ## Impact An attacker on the network path between the operator and the control plane can intercept user or admin API tokens and then act against the control plane as that user ## Affected configurations - `kumactl` profiles manually added against an HTTPS control plane endpoint without `--ca-cert-file` ## Not affected - The default local profile, which uses plain HTTP ## Workarounds When adding an H

O3 Security · Impact-Aware SCA

Is CVE-2026-50166 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works