The verdict in three sentences
In 2026, a web application security audit costs between 4,000 and 15,000 EUR excl. VAT depending on scope, and a full pentest between 6,000 and 20,000 EUR. Expect 1 to 3 weeks from kick-off to report, structured around the OWASP Top 10 with a prioritised remediation plan. The maths is simple: an audit costs a fraction of an exploited breach, which routinely runs into hundreds of thousands of euros.
Audit types and their deliverables
Securing an application before production combines several complementary approaches. Each covers a different attack surface.
| Audit type | What it covers | 2026 cost (EUR excl. VAT) | Timeline |
|---|---|---|---|
| Code audit (SAST) | Vulnerabilities in source code | 4,000 - 9,000 | 1 wk |
| Infrastructure audit | Servers, network, cloud config | 5,000 - 12,000 | 1-2 wks |
| Black-box pentest | External attack, no access | 6,000 - 14,000 | 1-2 wks |
| Grey-box pentest | Attack with user accounts | 9,000 - 20,000 | 2-3 wks |
| GDPR / data audit | Processing, data leakage | 4,000 - 10,000 | 1-2 wks |
| Post-remediation retest | Verifying fixes | 1,500 - 3,500 | 3-5 d |
The standard deliverable: a report ranking each vulnerability by severity (CVSS), with proof of exploitation, business impact and a fix recommendation.
The cost of an undetected flaw
An audit is justified by the risk avoided. Here are 2026 orders of magnitude for a European SME.
| Incident type | Estimated direct cost | Consequences |
|---|---|---|
| Customer data breach | 50,000 - 300,000 EUR | Regulator notice, lost trust |
| Ransomware | 40,000 - 250,000 EUR | 3-15 day downtime |
| Defacement / takeover | 10,000 - 60,000 EUR | Reputation, SEO, cleanup |
| GDPR fine | up to 4 % of revenue | Proceedings, forced compliance |
| Payment-flaw fraud | 20,000 - 150,000 EUR | Chargebacks, bank disputes |
An 8,000 EUR audit that prevents a single major incident shows immediate return on investment.
Mini case study
Raj, CTO of a B2B fintech in London (payments SaaS, 12,000 users), must reassure a large-account client before signing a 180,000 EUR/year contract. He commissions a grey-box pentest at 14,000 EUR plus a retest at 3,000 EUR.
The audit reveals two critical flaws (injection and broken access control) that, if exploited, would have exposed payment data. Total cost: 17,000 EUR to secure a 180,000 EUR contract and unlock three other prospects demanding the same proof. The pentest becomes a sales argument, not just a security expense.
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FAQ
What is the difference between an audit and a pentest?
An audit methodically examines code and configuration; a pentest simulates a real attack to prove exploitability. The two are complementary: the audit is broad, the pentest proves impact.
How often should an application be audited?
An audit before every major release, then annually, is a 2026 standard. Applications handling payments or sensitive data benefit from a six-month cadence.
Is the report enough, or must we fix?
The report only has value once remediation follows. Budget for fixes (often 20 to 50 % of the audit cost) and a retest to validate them.
Does an audit guarantee zero flaws?
No: it sharply reduces risk at a point in time. Security is continuous, which is why retests and post-launch monitoring matter.
How much is a post-fix retest?
Between 1,500 and 3,500 EUR depending on the number of vulnerabilities to revalidate. It is the only way to formally prove the flaws are closed.
Let's scope your project. Tell us the application type, the scope (code, infra, pentest) and your deadline, and we will define the audit and retest. 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.
