CORERO NETWORK SECURITY PLC — Share Issue/Capital Change 2026

May 13, 2026

National Storage Mechanism | Additional information

RNS Number : 2293E

Corero Network Security PLC

13 May 2026

13 May 2026

Corero Network Security plc

("Corero" or the "Company")

Blocklisting Return

The Company gives below the information required by Schedule 6 of the AIM Rules for Companies in connection with the Corero Network Security plc Unapproved Share Options Plan, the Enterprise Management Incentive (EMI) Plan and the Executive Enterprise Management Incentive (EMI) Plan (collectively the "Employee Share Schemes").

Name of applicant:		Corero Network Security plc
Name of scheme:		Corero Employee Share Schemes
Period of return:	From:	13 November 2025	To:	13 May 2026
Balance under scheme from previous return:		44,543,708 ordinary shares of 1 pence each
The amount by which the block scheme has been increased, if the scheme has been increased since the date of the last return:		N/A
Number of securities issued/allotted under scheme during period:		0 ordinary shares of 1 pence each
Balance under scheme not yet issued/allotted at end of period		44,543,708 ordinary shares of 1 pence each
Number and class of securities originally listed and the date of admission		61,856,538 ordinary shares of 1 pence each on 12 May 2022
Total number of securities in issue at the end of the period		512,165,134 ordinary shares of 1 pence each
Name of contact:		Chris Goulden
Telephone number of contact:		via Vigo Consulting

Enquiries:

Corero Network Security plc Carl Herberger, Chief Executive Officer	Tel: +44(0) 20 7390 0230
Chris Goulden, Chief Financial Officer
Canaccord Genuity Limited  (Nominated Adviser and Joint Broker) Simon Bridges / Andrew Potts / Harry Rees Zeus Capital (Joint Broker) Nick Searle / Ed Bellows	Tel: +44(0) 20 7523 8000 Tel: +44(0)20 3829 5000
Vigo Consulting (Financial PR & UK Investor Relations)	Tel: +44(0) 20 7390 0230
Jeremy Garcia / Anna Sutton [email protected]
Harbor Access (US Investor Relations)	Tel: +1 475 477 9401
Jonathan Paterson

About Corero Network Security

Corero Network Security is a leading provider of DDoS protection solutions, delivering real-time, automated detection and mitigation with deep network visibility and analytics. Corero safeguards critical infrastructure across diverse deployment models-from inline to edge to hybrid cloud-and is currently developing CORE, an observability and resiliency ecosystem to unify defensive actions across the modern threat landscape. With operational centres in Marlborough, Massachusetts, USA, and Edinburgh, UK, Corero is headquartered in London and listed on the London Stock Exchange's AIM market (ticker: CNS) and the US OTCQX Market (OTCQX: DDOSF).

For more information, visit www.corero.com, and follow us on LinkedIn and X.

This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact [email protected] or visit www.rns.com.

RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our Privacy Policy.

END

MSCGPUCPAUPQGQW