Vulnerability in Arqit Symmetric Key Agreement Platform

CVE-2026-33583

Exposure of the QKEY (used as input into the ‘OTA-Quantum’ device registration process) and internal system keys via an unauthenticated and unencrypted HTTP GET method in the Arqit Symmetric Key Agreement Platform. This issue affects Symmetric Key Agreement Platform: before 26.03.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (26.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-33583: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33583?
CVE-2026-33583 is a high-severity vulnerability in Arqit Symmetric Key Agreement Platform, classified under CWE-749. CVSS score: 8.7/10. Published 2026-05-13.
How severe is CVE-2026-33583?
High severity. CVSS v3 base score is 8.7 out of 10.