{"id":"CVE-2026-107579","revision":null,"records":[{"revision":"d41ce06d5e7a4e009bd53028226a1fdd","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-107579","aliases":[],"title":"Inefficient Algorithmic Complexity in hMailServer","description":"Inefficient algorithmic complexity in the bounce and complaint processing of Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to stop mail delivery by sending messages, when bounce processing or complaint processing is enabled or a mailing list is managed by the server (none is by default). The readers of incoming delivery status notifications (RFC 3464) and abuse feedback reports (RFC 5965) removed the blank lines at the start of the returned headers part two bytes at a time, copying the rest of the part each time, so their work grew with the square of the number of blank lines. A message shaped like such a report, whose headers part begins with a very large number of blank lines within the reader's 2 MB limit, keeps a delivery thread busy for over a minute while it is delivered, and a few such messages a minute keep every delivery thread busy.","state":0,"publishedAt":"2026-10-08T11:47:06.084+00:00","modifiedAt":"2026-10-08T14:18:19.902+00:00","affected":[{"ecosystem":"Vendor product","name":"hMailServer","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Progressive Robot Ltd\",\n                    \"product\": \"hMailServer\",\n                    \"repo\": \"https://gitlab.com/hmailserver/hmailserver\",\n                    \"versions\": [\n                        {\n                            \"version\": \"6.3.4\",\n                            \"status\": \"affected\",\n                            \"lessThan\": \"6.3.6\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://gitlab.com/hmailserver/hmailserver/-/work_items/70","https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-107579","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-107579","identifiers":["CVE-2026-107579"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-11T08:27:47.0671487+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-11T08:27:47.0671487+00:00","lastSuccessAt":"2026-11-11T08:27:47.385057+00:00","error":null,"lastVerifiedAt":"2026-11-11T08:27:47.3850582+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-de3b77103708811b6494d2ff7c979037d73ae579742cd1649a5c765137ae5083-bc1226ead32dcd8585c64680277f32c2227e36291dbe8f063e7519b0a52c9d06","complete":true,"records":423984,"lastAttemptAt":"2026-11-11T08:25:46.003985+00:00","lastSuccessAt":"2026-11-11T08:25:45.9381066+00:00","error":null,"lastVerifiedAt":"2026-11-11T08:25:46.003985+00:00","snapshotPublishedAt":"2026-11-11T07:28:36+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-a5bcdf6ab6d94076983501bc0e56dd96","complete":false,"records":13754,"lastAttemptAt":"2026-11-11T08:39:48.5063796+00:00","lastSuccessAt":"2026-11-11T08:39:48.502+00:00","error":"16 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-11T08:39:48.502+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13770,"expectedIdentifiers":13808,"failedIdentifiers":16},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-11T08:27:47.0671487+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-11T08:27:47.0671487+00:00","lastSuccessAt":"2026-11-11T08:27:47.3858436+00:00","error":null,"lastVerifiedAt":"2026-11-11T08:27:47.3858438+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-4463bca2214348638313ac7302b155ec","complete":true,"records":13748,"lastAttemptAt":"2026-11-11T08:27:47.8884887+00:00","lastSuccessAt":"2026-11-11T07:26:17.628+00:00","error":null,"lastVerifiedAt":"2026-11-11T07:26:17.628+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13808,"expectedIdentifiers":13808,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-11T08:27:46.9180255+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-11T08:27:46.9180255+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-11T08:25:46.0590741+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-11T08:25:46.0590741+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-0e3796c351bac632fda8fc3b3641da2bc6f0237cd79e78b1e59d17ce0aa22d32","complete":true,"records":3081,"lastAttemptAt":"2026-11-11T08:27:47.0269454+00:00","lastSuccessAt":"2026-11-10T20:24:10.5326555+00:00","error":null,"lastVerifiedAt":"2026-11-11T08:27:47.0269454+00:00","snapshotPublishedAt":"2026-11-10T20:03:04+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-085e065fc9050ae18408f7e722c39653aeb186872334d7b3ec1fcafb7ed43d25","complete":true,"records":231665,"lastAttemptAt":"2026-11-11T08:27:46.7420627+00:00","lastSuccessAt":"2026-11-11T08:27:45.2700102+00:00","error":null,"lastVerifiedAt":"2026-11-11T08:27:46.7420627+00:00","snapshotPublishedAt":"2026-11-11T07:32:59+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}