Symmetric Key Agreement Platform: Exposed Dangerous Method or Function
CVE-2026-33583 is a high-severity exposed dangerous method or function vulnerability in Symmetric Key Agreement Platform from Arqit, with a CVSS 3.1 base score of 8.7 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 26.03 as the first without the flaw, so updating Symmetric Key Agreement Platform to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Symmetric Key Agreement Platform to 26.03 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Arqit | Symmetric Key Agreement Platform | before 26.03 | 26.03 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N. Scored by CNA.
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Exposed Dangerous Method or Function
The product provides an Applications Programming Interface (API) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted.
How developers prevent this class of flaw
- If you must expose a method, make sure to perform input validation on all arguments, limit access to authorized parties, and protect against all possible vulnerabilities.
- Identify all exposed functionality. Explicitly list all functionality that must be exposed to some user or set of users. Identify which functionality may be: accessible to all users restricted to a small set of privileged users prevented from being directly accessible at all Ensure that the implemented code follows these expectations. This includes setting the appropriate access modifiers where applicable (public, private, protected, etc.) or not marking ActiveX controls safe-for-scripting.
More Exposed Dangerous Method or Function vulnerabilities (CWE-749)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Exposed Dangerous Method or Function vulnerabilities
- 8.5 High severity
- 8.1 High severity
- 9.9 Critical severity
- 9.9 Critical severity
- 8.1 High severity
- 7.5 High severity
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