What is CVE-2026-56402?

CVE-2026-56402 is a medium-severity vulnerability in Nanocoai Nanoclaw, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-06-23.

How severe is CVE-2026-56402?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Auth bypass in Nanocoai Nanoclaw

CVE-2026-56402

NanoClaw before 2.1.17 contains a privilege escalation vulnerability in the handleApprovalsResponse function that fails to verify responder role authorization. Attackers with a valid questionId can approve or reject privileged actions like package installation by submitting approval response payloads without proper role validation.

Vulnerability class: Broken Access Control

Published 2026-06-23 · last modified 2026-09-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (29.1th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Nanocoai Nanoclaw — versions 0, 2.1.17

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

github.com/nanocoai/nanoclaw/pull/2478 (issue-tracking, patch)
github.com/nanocoai/nanoclaw/commit/6227bd1a5b016fb1eb76411bb6681b4c924a51a0 (patch)
www.vulncheck.com/advisories/nanoclaw-privilege-escalation-via-unverified-appro… (third-party-advisory)

Frequently asked questions

What is CVE-2026-56402?: CVE-2026-56402 is a medium-severity vulnerability in Nanocoai Nanoclaw, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-06-23.
How severe is CVE-2026-56402?: Medium severity. CVSS v3 base score is 6.5 out of 10.