FKIE_CVE-2026-66370
Vulnerability from fkie_nvd - Published: 2026-08-06 16:16 - Updated: 2026-08-07 13:48
Severity
Summary
URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to retarget a form already on the rendering page and receive whatever the victim submits, including credentials, via the form and formaction attributes on an <input> element in sanitized HTML. HTML's form attribute associates an input with any form on the page by its id even when the input sits outside that form, and formaction on a submit control overrides the owning form's action. Neither attribute receives a scheme check, so an absolute cross-origin URL survives sanitizing.
No script executes. The scrubber allows neither form nor button, so the attacker cannot introduce a form of their own and the rendering page must already contain a form carrying an id.
This issue affects html_sanitize_ex: from 0.3.1 before 1.5.3.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"collectionURL": "https://repo.hex.pm",
"cpes": [
"cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"Elixir.HtmlSanitizeEx.Scrubber.HTML5",
"Elixir.HtmlSanitizeEx"
],
"packageName": "html_sanitize_ex",
"packageURL": "pkg:hex/html_sanitize_ex",
"product": "html_sanitize_ex",
"programFiles": [
"lib/html_sanitize_ex/scrubber/html5.ex",
"lib/html_sanitize_ex.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.HtmlSanitizeEx.Scrubber.HTML5\u0027:scrub_attribute/2"
},
{
"name": "\u0027Elixir.HtmlSanitizeEx.Scrubber.HTML5\u0027:sanitize/1"
},
{
"name": "\u0027Elixir.HtmlSanitizeEx\u0027:html5/1"
}
],
"repo": "https://github.com/rrrene/html_sanitize_ex",
"vendor": "rrrene",
"versions": [
{
"lessThan": "1.5.3",
"status": "affected",
"version": "0.3.1",
"versionType": "semver"
}
]
},
{
"collectionURL": "https://github.com",
"cpes": [
"cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"Elixir.HtmlSanitizeEx.Scrubber.HTML5",
"Elixir.HtmlSanitizeEx"
],
"packageName": "rrrene/html_sanitize_ex",
"packageURL": "pkg:github/rrrene/html_sanitize_ex",
"product": "html_sanitize_ex",
"programFiles": [
"lib/html_sanitize_ex/scrubber/html5.ex",
"lib/html_sanitize_ex.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.HtmlSanitizeEx.Scrubber.HTML5\u0027:scrub_attribute/2"
},
{
"name": "\u0027Elixir.HtmlSanitizeEx.Scrubber.HTML5\u0027:sanitize/1"
},
{
"name": "\u0027Elixir.HtmlSanitizeEx\u0027:html5/1"
}
],
"repo": "https://github.com/rrrene/html_sanitize_ex",
"vendor": "rrrene",
"versions": [
{
"lessThan": "a1e804ed997e780ea71d14393cf2f701330553a6",
"status": "affected",
"version": "8976d64ea0b77d26093a94a43ec48a3978e8d028",
"versionType": "git"
}
]
}
],
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "URL Redirection to Untrusted Site (\u0027Open Redirect\u0027) vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to retarget a form already on the rendering page and receive whatever the victim submits, including credentials, via the form and formaction attributes on an \u003cinput\u003e element in sanitized HTML. HTML\u0027s form attribute associates an input with any form on the page by its id even when the input sits outside that form, and formaction on a submit control overrides the owning form\u0027s action. Neither attribute receives a scheme check, so an absolute cross-origin URL survives sanitizing.\n\nNo script executes. The scrubber allows neither form nor button, so the attacker cannot introduce a form of their own and the rendering page must already contain a form carrying an id.\n\nThis issue affects html_sanitize_ex: from 0.3.1 before 1.5.3."
}
],
"id": "CVE-2026-66370",
"lastModified": "2026-08-07T13:48:52.300",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 4.8,
"baseSeverity": "MEDIUM",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "HIGH",
"subIntegrityImpact": "LOW",
"userInteraction": "ACTIVE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-66370",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-06T15:42:03.803831Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-06T16:16:48.420",
"references": [
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://cna.erlef.org/cves/CVE-2026-66370.html"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/rrrene/html_sanitize_ex/commit/a1e804ed997e780ea71d14393cf2f701330553a6"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-w3f9-jjhw-wwvq"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-66370"
}
],
"sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"vulnStatus": "Undergoing Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-601"
}
],
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"type": "Secondary"
}
]
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…