{"id":"CVE-2026-42304","state":"PUBLISHED","title":"Twisted: Denial of Service (DoS) in twisted.names via Crafted DNS Compression Pointer Chains","description":"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.","publishedAt":"2026-05-13T20:20:29.149Z","updatedAt":"2026-05-14T15:45:34.746Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["twisted twisted"],"affected":[{"vendor":"twisted","product":"twisted","versions":[{"version":"< 26.4.0rc2","status":"affected"}]}],"references":["https://github.com/twisted/twisted/security/advisories/GHSA-grgv-6hw6-v9g4"],"weaknesses":["CWE-400","CWE-407"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/42xxx/CVE-2026-42304.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42304","state":"PUBLISHED","datePublished":"2026-05-13T20:20:29.149Z","dateUpdated":"2026-05-14T15:45:34.746Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-26T12:13:55.552Z"},"containers":{"cna":{"title":"Twisted: Denial of Service (DoS) in twisted.names via Crafted DNS Compression Pointer Chains","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"twisted","product":"twisted","versions":[{"version":"< 26.4.0rc2","status":"affected"}]}],"references":[{"url":"https://github.com/twisted/twisted/security/advisories/GHSA-grgv-6hw6-v9g4","name":"https://github.com/twisted/twisted/security/advisories/GHSA-grgv-6hw6-v9g4","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-407","lang":"en","description":"CWE-407: Inefficient Algorithmic Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-13T20:20:29.149Z"},"source":{"advisory":"GHSA-grgv-6hw6-v9g4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/twisted/twisted/security/advisories/GHSA-grgv-6hw6-v9g4","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-14T15:44:57.486318Z","id":"CVE-2026-42304","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-14T15:45:34.746Z"}}]}}}