{"schema":"threatline.record/2","record":{"id":"CVE-2026-107575","aliases":[],"summary":"Inefficient Algorithmic Complexity in hMailServer","details":"Inefficient algorithmic complexity in the SPF macro expansion of Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to consume worker-thread time by publishing a crafted SPF record. RFC 7208 section 7.1 requires a name too long to look up to lose whole labels from the left; the server did this by removing one label at a time and copying the rest of the name each time, so the work grew with the square of the expansion. An attacker who publishes an SPF record for a domain they control, with a mechanism whose domain-spec expands through macros to a name far longer than 253 characters, makes the SPF check of a message from that domain take several seconds. The expansion is bounded by SPF's own per-term and per-macro limits, so the loss of availability is partial.","categories":["Unclassified"],"product":"hMailServer","vendor":"Progressive Robot Ltd","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-107575","source_modified_at":"2026-10-08T14:17:04.989Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"hMailServer","vendor":"Progressive Robot Ltd","versions":[{"version":"6.3.4","status":"affected","lessThan":"6.3.6","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-107575","source_modified_at":"2026-10-08T14:17:04.989Z","fetched_at":"2026-10-23T18:48:36.087640Z","package":{"name":"hMailServer","ecosystem":null},"version":"6.3.6","basis":"first unaffected version stated in the CVE record"}],"cvss":5.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00387,"percentile":0.31627,"score_date":"2026-10-23"},"published_at":"2026-10-08T11:46:46.082Z","modified_at":"2026-10-08T14:17:04.989Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-107575","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-08T14:17:04.989Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-107575","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://gitlab.com/hmailserver/hmailserver/-/work_items/74"},{"source":"CVE List","url":"https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"partial","assessed_at":"2026-10-08T14:16:55.314371Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-08T14:17:04.989Z","content_hash":"a2de29930fdb8130d91738a2b172b275b7cda2c89f253a65b50e4ab499df33e2"}}