CVE-2026-42304 — Twisted: Denial of Service (DoS) in twisted.names via Crafted DNS Compression Pointer Chains
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) at…
Published: 2026-05-13 · CVSS: 7.5 · CVSS 3.1
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can exploit this by sending a crafted TCP DNS packet containing deeply chained compression pointers. This flaw bypasses previous loop-prevention logic, causing the single-threaded Twisted reactor to hang while processing millions of recursive lookups, effectively freezing the server. This vulnerability is fixed in 26.4.0rc2.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7