{"id":"CVE-2026-77972","summary":"safeurl validated address is not bound to the request, allowing DNS rebinding","details":"Time-of-check Time-of-use (TOCTOU) Race Condition in Slab safeurl allows an attacker who controls a hostname's DNS responses to reach internal network destinations that validation rejected.\n\nValidation returns a verdict and not the address it approved, so the HTTP clients the library ships receive the original hostname and resolve it a second time when the request is made. An attacker who controls the authoritative DNS for a name can answer the first lookup with a permitted address and the second with a blocked one, and the request then reaches a destination validation never approved. The same window opens without an attacker whenever a name legitimately resolves to different addresses across lookups, such as short record lifetimes or rotation between several addresses.\n\nThis issue affects safeurl: from 0.1.0 onward.","aliases":["EEF-CVE-2026-77972"],"modified":"2026-09-23T03:30:27.432987500Z","published":"2026-09-15T15:37:49.948Z","database_specific":{"cna_assigner":"EEF","cwe_ids":["CWE-367"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77972.json","unresolved_ranges":[{"extracted_events":[{"introduced":"0.1.0"},{"fixed":"*"},{"introduced":"feabbd0a13f83028ab24b71710526e9da9841f70"},{"fixed":"*"}],"source":"AFFECTED_FIELD"}]},"references":[{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-77972"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://cna.erlef.org/cves/CVE-2026-77972.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77972.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77972"},{"type":"FIX","url":"https://github.com/slab/safeurl-elixir/commit/feabbd0a13f83028ab24b71710526e9da9841f70"},{"type":"PACKAGE","url":"https://github.com/slab/safeurl-elixir"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/slab/safeurl-elixir","events":[{"introduced":"0"},{"fixed":"feabbd0a13f83028ab24b71710526e9da9841f70"}],"database_specific":{"source":"REFERENCES"}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-77972.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N"}]}