Hacker's Playground

ISSUEN°11 ·2026

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N°00 · ABOUT · ATABERK

whoami

Senior Security Engineer at Midas. 7+ years across smart contract audits and offensive security. I break things, then build tools so they break less.

OPERATOR
Ataberk · ataberk-xyz
ROLE
Senior Security Engineer @ Midas
CONTRACTS
Solidity · EVM · Move (Aptos, Sui)
OFFENSIVE
Active Directory · web & network
LLM & AGENTS
gossipcat · MCP · Claude Code · LLM & agent pentest
TOOLING
Foundry · Python · TypeScript
CERTS
OSCP · OSWE · CRTP · C-AI/MLPen
TRACK
ex-Hacken (Principal) · ex-Halborn (Lead)
SINCE
August 2026 · İstanbul
STATUS
BREAKING THINGS ✓

I'm a Senior Security Engineer at Midas. Before that, Principal Smart Contract Auditor at Hacken (2023–2026) and Lead Offensive Security Engineer at Halborn. I started out in penetration testing — web apps, networks, Active Directory — and moved into smart contract security. I also build tooling like gossipcat-ai.

Certifications

Recognition

n-day research on a Microsoft SQL Server stack overflow — analyzed the bug, wrote a working exploit (writeup)CVE-2019-1068
T-Mobile Hall of Fame — XSS, SQLi, RCEHOF
Mail.ru Hall of Fame — Cross-Site ScriptingHOF
gossipcat-ai — multi-agent code-review orchestrator (TypeScript / MCP); agents cross-verify findings against real code to filter hallucinationsOSS

Security advisories

Found and responsibly disclosed in widely-used software.

PackageAdvisorySeverityImpact
install-artifact-from-github GHSA-88q3-gch3-5396 HIGH 7.5 CWE-494 native addon downloaded over the network and loaded with no integrity check → install-time RCE
stream-json CVE-2026-71429 MEDIUM 6.2 CWE-407 quadratic path filters → a small nested JSON blocks the event loop. Fixed in 3.5.0
node-re2 CVE-2026-68499 MEDIUM 6.2 CWE-835 zero-width global match never advances → infinite loop, unbounded native memory. Fixed in 1.25.2
node-re2 CVE-2026-67550 MEDIUM 5.7 CWE-125 attacker-influenced lastIndex on a non-ASCII subject → out-of-bounds heap read, uncatchable crash
node-re2 CVE-2026-71430 MEDIUM 6.2 CWE-617 replace with an output-amplifying template aborts Node past V8's max string length
Kentico CMS CVE-2019-19493 MEDIUM 5.4 CWE-434 upload whose Content-Type disagrees with its extension → stored XSS (≤ 12.0.49). Fixed in 12.0.50

Skills

Offensive
Internal & external pentest · Active Directory attack paths (Kerberoasting, NTLM relaying, Pass-the-Hash) · phishing & social engineering
Smart contracts
Audit delivery · DeFi threat modeling · invariant & PoC development
Vuln research
n-day research · patch diffing · fuzzing & crash minimisation · coordinated disclosure
Orchestration
Multi-agent review pipelines · consensus verification & hallucination filtering