{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-77972", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-08-24T15:45:02.127Z", "datePublished": "2026-09-15T15:37:49.948Z", "dateUpdated": "2026-09-21T18:44:16.787Z" }, "containers": { "cna": { "affected": [ { "collectionURL": "https://repo.hex.pm", "cpes": [ "cpe:2.3:a:slab:safeurl:*:*:*:*:*:*:*:*" ], "defaultStatus": "unaffected", "modules": [ "'Elixir.SafeURL'", "'Elixir.SafeURL.HTTPoison'", "'Elixir.SafeURL.TeslaMiddleware'" ], "packageName": "safeurl", "packageURL": "pkg:hex/safeurl", "product": "safeurl", "programFiles": [ "lib/safeurl/safeurl.ex", "lib/safeurl/httpoison.ex", "lib/safeurl/tesla_middleware.ex" ], "programRoutines": [ { "name": "'Elixir.SafeURL':validate/2" }, { "name": "'Elixir.SafeURL.HTTPoison':get/3" }, { "name": "'Elixir.SafeURL.TeslaMiddleware':call/3" } ], "repo": "https://github.com/slab/safeurl-elixir", "vendor": "Slab", "versions": [ { "lessThan": "*", "status": "affected", "version": "0.1.0", "versionType": "semver" } ] }, { "collectionURL": "https://github.com", "cpes": [ "cpe:2.3:a:slab:safeurl:*:*:*:*:*:*:*:*" ], "defaultStatus": "unaffected", "modules": [ "'Elixir.SafeURL'", "'Elixir.SafeURL.HTTPoison'", "'Elixir.SafeURL.TeslaMiddleware'" ], "packageName": "slab/safeurl-elixir", "packageURL": "pkg:github/slab/safeurl-elixir", "product": "safeurl", "programFiles": [ "lib/safeurl/safeurl.ex", "lib/safeurl/httpoison.ex", "lib/safeurl/tesla_middleware.ex" ], "programRoutines": [ { "name": "'Elixir.SafeURL':validate/2" }, { "name": "'Elixir.SafeURL.HTTPoison':get/3" }, { "name": "'Elixir.SafeURL.TeslaMiddleware':call/3" } ], "repo": "https://github.com/slab/safeurl-elixir", "vendor": "Slab", "versions": [ { "lessThan": "*", "status": "affected", "version": "feabbd0a13f83028ab24b71710526e9da9841f70", "versionType": "git" } ] } ], "cpeApplicability": [ { "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:a:slab:safeurl:*:*:*:*:*:*:*:*", "versionStartIncluding": "0.1.0", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "AND" } ], "credits": [ { "lang": "en", "type": "reporter", "value": "Jonatan Männchen / EEF" }, { "lang": "en", "type": "coordinator", "value": "Jonatan Männchen / EEF" } ], "descriptions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

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

Validation 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

This issue affects safeurl: from 0.1.0 onward.

" }, { "base64": false, "type": "text/markdown", "value": "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." } ], "value": "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." } ], "impacts": [ { "capecId": "CAPEC-664", "descriptions": [ { "lang": "en", "value": "CAPEC-664 Server Side Request Forgery" } ] } ], "metrics": [ { "cvssV4_0": { "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 9, "baseSeverity": "CRITICAL", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-367", "description": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition", "lang": "en", "type": "CWE" } ] } ], "providerMetadata": { "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-09-15T15:37:49.948Z" }, "references": [ { "name": "EEF CNA record for CVE-2026-77972", "tags": [ "related", "third-party-advisory" ], "url": "https://cna.erlef.org/cves/CVE-2026-77972.html" }, { "name": "OSV record EEF-CVE-2026-77972", "tags": [ "related" ], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-77972" }, { "name": "Introducing commit feabbd0 in slab/safeurl-elixir", "tags": [ "related" ], "url": "https://github.com/slab/safeurl-elixir/commit/feabbd0a13f83028ab24b71710526e9da9841f70" } ], "source": { "discovery": "EXTERNAL" }, "title": "safeurl validated address is not bound to the request, allowing DNS rebinding" }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-09-21T18:44:04.900610Z", "id": "CVE-2026-77972", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-21T18:44:16.787Z" } } ] } }