Scheme validation bypass in Phoenix.LiveView.Utils leads to XSS via <.link>

Summary

CVECVE-2026-58228
StatePUBLISHED
AssignerEEF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-13 19:17:30 UTC
Updated2026-07-13 20:37:48 UTC
DescriptionCross-site scripting vulnerability in phoenixframework phoenix_live_view allows an attacker to bypass URL scheme validation and execute JavaScript in a victim's browser session. The Phoenix.LiveView.Utils.valid_destination!/2 and Phoenix.LiveView.Utils.valid_live_navigation_destination!/2 functions in lib/phoenix_live_view/utils.ex rely on an internal uri_scheme/1 helper that only detects a scheme when the input's first byte is an ASCII letter. Inputs beginning with an ASCII control character or space fall through to a nil-returning clause, causing the URL to be treated as a safe relative path. Standard browsers implement the WHATWG URL parser, which strips leading C0 control and space characters before parsing. As a result, an input such as " javascript:alert(1)" is passed unchanged into <.link href={...}> and, when clicked, is parsed by the browser as a javascript: URL that executes attacker-controlled script in the victim's session. Applications that render user-supplied URLs (for example profile links, redirect targets, or external references) via <.link href={...}> are affected. This issue affects phoenix_live_view: from 1.2.2 before 1.2.7.

Risk And Classification

Primary CVSS: v4.0 5.1 MEDIUM from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:H/SI:H/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

Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')


VersionSourceTypeScoreSeverityVector
4.06b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary5.1MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N/E:X/C...
4.0CNACVSS5.1MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
Active
Confidentiality
Low
Integrity
Low
Availability
None
Sub Conf.
High
Sub Integrity
High
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:H/SI:H/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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Phoenixframework Phoenix Live View affected 1.2.2 1.2.7 semver Not specified
CNA Phoenixframework Phoenix Live View affected 4b63216ae68886db99cf7772af23372d76c40e7e 86165533e311469a1b62093fd182d9d874de8106 git Not specified

References

ReferenceSourceLinkTags
github.com/phoenixframework/phoenix_live_view/security/advisories/GHSA-5... 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com
cna.erlef.org/cves/CVE-2026-58228.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db cna.erlef.org
osv.dev/vulnerability/EEF-CVE-2026-58228 6b3ad84c-e1a6-4bf7-a703-f496b71e49db osv.dev
github.com/phoenixframework/phoenix_live_view/commit/86165533e311469a1b6... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Barna Kovacs (en)

CNA: Steffen Deusch (en)

CNA: José Valim (en)

CNA: Jonatan Männchen / EEF (en)

Additional Advisory Data

Workarounds

CNA: Strip leading ASCII control and space bytes (code points 0x00 through 0x20) from any untrusted URL before passing it to <.link href={...}>, or reject such inputs outright. This aligns application-level validation with the WHATWG URL parser used by browsers and prevents the scheme-detection bypass.

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