The verdict in three sentences
A security audit with a pentest finds your flaws before attackers do, when they are cheapest to fix. In 2026 in Dublin, budget 6,000 to 18,000 EUR and 2 to 4 weeks for an OWASP test with a prioritised report and a verification re-test. Compared with the average cost of a data breach, counted in tens or hundreds of thousands of euros, it is one of the best-returning security investments.
What a pentest costs by scope
Price depends mostly on the access given to the tester and the surface to cover. Here are the 2026 ranges.
| Scope | Description | 2026 cost (EUR) | Timeline |
|---|---|---|---|
| Black box | No access or account | 6,000 - 10,000 | 1-2 wk |
| Grey box | With user accounts | 9,000 - 15,000 | 2-3 wk |
| White box | Code + architecture access | 12,000 - 18,000 | 3-4 wk |
| Dedicated API test | Endpoints + auth | 5,000 - 10,000 | 1-2 wk |
| Verification re-test | Fix validation | 1,500 - 3,500 | 3-5 d |
Grey box is the best coverage-to-cost ratio for most business apps: the tester simulates an already-authenticated malicious user.
Common flaws and the cost of a breach
2026 reports are still dominated by the same OWASP categories. Here are the most common ones and their potential impact.
| Flaw | Observed frequency | Typical impact |
|---|---|---|
| Broken access control (IDOR) | 40 % of apps | Access to other clients' data |
| Injection (SQL, command) | 20 % | Database theft/alteration |
| Weak authentication | 30 % | Account takeover |
| Misconfig/exposed secrets | 35 % | Server compromise |
| Vulnerable dependencies | 50 % | Known exploit |
In the EU, a personal-data breach exposes you to a regulator sanction and, for an SME, a total cost (technical, legal, reputation) commonly in the 50,000 to 300,000 EUR range. A pentest, at a fraction of that, shifts the risk to the right side.
Mini case study
Mehdi, IT director of a 60-person health scale-up in Dublin, had to secure an app handling patient data before go-live. We ran a grey-box pentest at 12,500 EUR, revealing two critical IDORs and a vulnerable dependency. Remediation cost 4 dev days (about 2,400 EUR), followed by a 2,000 EUR re-test. Total security budget: 16,900 EUR, against a breach risk estimated above 150,000 EUR. The report also reassured an enterprise client in the buying phase, unlocking a contract.
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FAQ
Black, grey or white box, which to choose?
Grey box offers the best ratio for a business app: it simulates an authenticated user and covers the most frequent flaws. White box is reserved for highly critical apps.
Is the re-test really necessary?
Yes. Fixing without re-testing leaves doubt. The re-test confirms the flaws are truly closed and provides a clean report, often required by your clients or insurers.
How often should I redo a pentest?
At least once a year, and systematically after a major change (new sensitive feature, authentication rework, migration).
How much does remediation cost?
Variable depending on the flaws found, often 2 to 8 dev days. A good report prioritises fixes so critical items are handled first.
Does a pentest guarantee total security?
No, no method does. It sharply reduces risk by eliminating known, exploitable flaws, and proves your due diligence in case of audit.
Let's scope your project. Tell us the app type, the data it handles and your go-live date, and we will frame the right pentest scope. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
