🛡️ CVE-2026-42533

The items that name it 2

• Orca Security: Critical Heap Buffer Overflow in NGINX Allows Unauthenticated RCE
  advisory2026-07-20It is written here as CVE-2026-42533 (NGINX map directive regex heap buffer overflow, CWE-122; CVSS v4.0 9.2 / CVSS v3.1 8.1; unauthenticated RCE/DoS).

  NGINX map directive regex heap buffer overflow, CWE-122; CVSS v4.0 9.2 / CVSS v3.1 8.1; unauthenticated RCE/DoS

• CVE-2026-42533 nginx heap buffer overflow PoC (pre-auth RCE via two-pass capture clobbering)
  repo

  Critical heap buffer overflow in nginx's two-pass string evaluation engine, occurring when a regex-based map directive interacts with numbered capture groups ($1, $2, etc.), silently overwriting the shared r->captures structure between the LEN (measure) and VALUE (write) passes, causing a size misma