Search
Find a vulnerability
Search criteria
ⓘ
Use this form to refine search results.
Full-text search supports keyword queries with ranking and filtering.
You can combine vendor, product, and sources to narrow results.
Enable “Apply ordering” to sort by date instead of relevance.
4 vulnerabilities found for safeurl by Slab
CVE-2026-77972 (GCVE-0-2026-77972)
Vulnerability from nvd – Published: 2026-09-15 15:37 – Updated: 2026-09-15 15:37
VLAI
EPSS
VEX
Title
safeurl validated address is not bound to the request, allowing DNS rebinding
Summary
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.
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.
This issue affects safeurl: from 0.1.0 onward.
Severity
CWE
- CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-77972.html | relatedthird-party-advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-77972 | related |
| https://github.com/slab/safeurl-elixir/commit/fea… | related |
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"collectionURL": "https://repo.hex.pm",
"cpes": [
"cpe:2.3:a:slab:safeurl:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"\u0027Elixir.SafeURL\u0027",
"\u0027Elixir.SafeURL.HTTPoison\u0027",
"\u0027Elixir.SafeURL.TeslaMiddleware\u0027"
],
"packageName": "safeurl",
"packageURL": "pkg:hex/safeurl",
"product": "safeurl",
"programFiles": [
"lib/safeurl/safeurl.ex",
"lib/safeurl/httpoison.ex",
"lib/safeurl/tesla_middleware.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL.HTTPoison\u0027:get/3"
},
{
"name": "\u0027Elixir.SafeURL.TeslaMiddleware\u0027: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": [
"\u0027Elixir.SafeURL\u0027",
"\u0027Elixir.SafeURL.HTTPoison\u0027",
"\u0027Elixir.SafeURL.TeslaMiddleware\u0027"
],
"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": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL.HTTPoison\u0027:get/3"
},
{
"name": "\u0027Elixir.SafeURL.TeslaMiddleware\u0027: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 M\u00e4nnchen / EEF"
},
{
"lang": "en",
"type": "coordinator",
"value": "Jonatan M\u00e4nnchen / EEF"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eTime-of-check Time-of-use (TOCTOU) Race Condition in Slab safeurl allows an attacker who controls a hostname\u0027s DNS responses to reach internal network destinations that validation rejected.\u003c/p\u003e\n\u003cp\u003eValidation 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.\u003c/p\u003e\n\u003cp\u003eThis issue affects safeurl: from 0.1.0 onward.\u003c/p\u003e"
},
{
"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\u0027s 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\u0027s 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": {
"dateUpdated": "2026-09-15T15:37:49.948Z",
"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"shortName": "EEF"
},
"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"
}
},
"cveMetadata": {
"assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"assignerShortName": "EEF",
"cveId": "CVE-2026-77972",
"datePublished": "2026-09-15T15:37:49.948Z",
"dateReserved": "2026-08-24T15:45:02.127Z",
"dateUpdated": "2026-09-15T15:37:49.948Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-77866 (GCVE-0-2026-77866)
Vulnerability from nvd – Published: 2026-09-15 15:38 – Updated: 2026-09-15 15:39
VLAI
EPSS
VEX
Title
SSRF protection bypass in safeurl via IPv6 addresses and unresolvable hosts
Summary
Server-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.
Only IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.
This issue affects safeurl: from 0.1.0 onward.
Severity
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-77866.html | relatedthird-party-advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-77866 | related |
| https://github.com/slab/safeurl-elixir/commit/fea… | related |
Impacted products
Date Public
2026-09-15 15:38
{
"containers": {
"cna": {
"affected": [
{
"collectionURL": "https://repo.hex.pm",
"cpes": [
"cpe:2.3:a:slab:safeurl:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"\u0027Elixir.SafeURL\u0027"
],
"packageName": "safeurl",
"packageURL": "pkg:hex/safeurl",
"product": "safeurl",
"programFiles": [
"lib/safeurl/safeurl.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL\u0027:allowed?/2"
}
],
"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": [
"\u0027Elixir.SafeURL\u0027"
],
"packageName": "slab/safeurl-elixir",
"packageURL": "pkg:github/slab/safeurl-elixir",
"product": "safeurl",
"programFiles": [
"lib/safeurl/safeurl.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL\u0027:allowed?/2"
}
],
"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": "Mathias Polligkeit"
},
{
"lang": "en",
"type": "coordinator",
"value": "Jonatan M\u00e4nnchen / EEF"
}
],
"datePublic": "2026-09-15T15:38:16.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eServer-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.\u003c/p\u003e\n\u003cp\u003eOnly IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.\u003c/p\u003e\n\u003cp\u003eThis issue affects safeurl: from 0.1.0 onward.\u003c/p\u003e"
},
{
"base64": false,
"type": "text/markdown",
"value": "Server-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.\n\nOnly IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.\n\nThis issue affects safeurl: from 0.1.0 onward."
}
],
"value": "Server-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.\n\nOnly IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.\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": "LOW",
"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:L/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-918",
"description": "CWE-918 Server-Side Request Forgery (SSRF)",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-636",
"description": "CWE-636 Not Failing Securely (\u0027Failing Open\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-15T15:39:37.321Z",
"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"shortName": "EEF"
},
"references": [
{
"name": "EEF CNA record for CVE-2026-77866",
"tags": [
"related",
"third-party-advisory"
],
"url": "https://cna.erlef.org/cves/CVE-2026-77866.html"
},
{
"name": "OSV record EEF-CVE-2026-77866",
"tags": [
"related"
],
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-77866"
},
{
"name": "Introducing commit feabbd0 in slab/safeurl-elixir",
"tags": [
"related"
],
"url": "https://github.com/slab/safeurl-elixir/commit/feabbd0a13f83028ab24b71710526e9da9841f70"
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "SSRF protection bypass in safeurl via IPv6 addresses and unresolvable hosts"
}
},
"cveMetadata": {
"assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"assignerShortName": "EEF",
"cveId": "CVE-2026-77866",
"datePublished": "2026-09-15T15:38:15.886Z",
"dateReserved": "2026-08-30T00:00:01.985Z",
"dateUpdated": "2026-09-15T15:39:37.321Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-77866 (GCVE-0-2026-77866)
Vulnerability from cvelistv5 – Published: 2026-09-15 15:38 – Updated: 2026-09-15 15:39
VLAI
EPSS
VEX
Title
SSRF protection bypass in safeurl via IPv6 addresses and unresolvable hosts
Summary
Server-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.
Only IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.
This issue affects safeurl: from 0.1.0 onward.
Severity
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-77866.html | relatedthird-party-advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-77866 | related |
| https://github.com/slab/safeurl-elixir/commit/fea… | related |
Impacted products
Date Public
2026-09-15 15:38
{
"containers": {
"cna": {
"affected": [
{
"collectionURL": "https://repo.hex.pm",
"cpes": [
"cpe:2.3:a:slab:safeurl:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"\u0027Elixir.SafeURL\u0027"
],
"packageName": "safeurl",
"packageURL": "pkg:hex/safeurl",
"product": "safeurl",
"programFiles": [
"lib/safeurl/safeurl.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL\u0027:allowed?/2"
}
],
"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": [
"\u0027Elixir.SafeURL\u0027"
],
"packageName": "slab/safeurl-elixir",
"packageURL": "pkg:github/slab/safeurl-elixir",
"product": "safeurl",
"programFiles": [
"lib/safeurl/safeurl.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL\u0027:allowed?/2"
}
],
"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": "Mathias Polligkeit"
},
{
"lang": "en",
"type": "coordinator",
"value": "Jonatan M\u00e4nnchen / EEF"
}
],
"datePublic": "2026-09-15T15:38:16.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eServer-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.\u003c/p\u003e\n\u003cp\u003eOnly IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.\u003c/p\u003e\n\u003cp\u003eThis issue affects safeurl: from 0.1.0 onward.\u003c/p\u003e"
},
{
"base64": false,
"type": "text/markdown",
"value": "Server-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.\n\nOnly IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.\n\nThis issue affects safeurl: from 0.1.0 onward."
}
],
"value": "Server-Side Request Forgery (SSRF) vulnerability in Slab safeurl allows an attacker who controls a validated URL to reach internal network destinations the library is configured to block.\n\nOnly IPv4 addresses are matched against the reserved ranges and the blocklist. Every other address is treated as matching nothing, so a destination that is rejected in its IPv4 form is accepted when written as an IPv6 address, IPv6 entries in the blocklist never match, and a host that resolves to no IPv4 address is accepted regardless of where it points. Deployments that rely on the allowlist instead are unaffected, because there an unmatched address is rejected.\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": "LOW",
"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:L/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-918",
"description": "CWE-918 Server-Side Request Forgery (SSRF)",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-636",
"description": "CWE-636 Not Failing Securely (\u0027Failing Open\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-15T15:39:37.321Z",
"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"shortName": "EEF"
},
"references": [
{
"name": "EEF CNA record for CVE-2026-77866",
"tags": [
"related",
"third-party-advisory"
],
"url": "https://cna.erlef.org/cves/CVE-2026-77866.html"
},
{
"name": "OSV record EEF-CVE-2026-77866",
"tags": [
"related"
],
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-77866"
},
{
"name": "Introducing commit feabbd0 in slab/safeurl-elixir",
"tags": [
"related"
],
"url": "https://github.com/slab/safeurl-elixir/commit/feabbd0a13f83028ab24b71710526e9da9841f70"
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "SSRF protection bypass in safeurl via IPv6 addresses and unresolvable hosts"
}
},
"cveMetadata": {
"assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"assignerShortName": "EEF",
"cveId": "CVE-2026-77866",
"datePublished": "2026-09-15T15:38:15.886Z",
"dateReserved": "2026-08-30T00:00:01.985Z",
"dateUpdated": "2026-09-15T15:39:37.321Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-77972 (GCVE-0-2026-77972)
Vulnerability from cvelistv5 – Published: 2026-09-15 15:37 – Updated: 2026-09-15 15:37
VLAI
EPSS
VEX
Title
safeurl validated address is not bound to the request, allowing DNS rebinding
Summary
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.
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.
This issue affects safeurl: from 0.1.0 onward.
Severity
CWE
- CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-77972.html | relatedthird-party-advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-77972 | related |
| https://github.com/slab/safeurl-elixir/commit/fea… | related |
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"collectionURL": "https://repo.hex.pm",
"cpes": [
"cpe:2.3:a:slab:safeurl:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"\u0027Elixir.SafeURL\u0027",
"\u0027Elixir.SafeURL.HTTPoison\u0027",
"\u0027Elixir.SafeURL.TeslaMiddleware\u0027"
],
"packageName": "safeurl",
"packageURL": "pkg:hex/safeurl",
"product": "safeurl",
"programFiles": [
"lib/safeurl/safeurl.ex",
"lib/safeurl/httpoison.ex",
"lib/safeurl/tesla_middleware.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL.HTTPoison\u0027:get/3"
},
{
"name": "\u0027Elixir.SafeURL.TeslaMiddleware\u0027: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": [
"\u0027Elixir.SafeURL\u0027",
"\u0027Elixir.SafeURL.HTTPoison\u0027",
"\u0027Elixir.SafeURL.TeslaMiddleware\u0027"
],
"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": "\u0027Elixir.SafeURL\u0027:validate/2"
},
{
"name": "\u0027Elixir.SafeURL.HTTPoison\u0027:get/3"
},
{
"name": "\u0027Elixir.SafeURL.TeslaMiddleware\u0027: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 M\u00e4nnchen / EEF"
},
{
"lang": "en",
"type": "coordinator",
"value": "Jonatan M\u00e4nnchen / EEF"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eTime-of-check Time-of-use (TOCTOU) Race Condition in Slab safeurl allows an attacker who controls a hostname\u0027s DNS responses to reach internal network destinations that validation rejected.\u003c/p\u003e\n\u003cp\u003eValidation 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.\u003c/p\u003e\n\u003cp\u003eThis issue affects safeurl: from 0.1.0 onward.\u003c/p\u003e"
},
{
"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\u0027s 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\u0027s 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": {
"dateUpdated": "2026-09-15T15:37:49.948Z",
"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"shortName": "EEF"
},
"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"
}
},
"cveMetadata": {
"assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"assignerShortName": "EEF",
"cveId": "CVE-2026-77972",
"datePublished": "2026-09-15T15:37:49.948Z",
"dateReserved": "2026-08-24T15:45:02.127Z",
"dateUpdated": "2026-09-15T15:37:49.948Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}