Vuln Signal Radar
public-safe defensive signal
Agent JSON
MEDIUMpublic-safe

CVE-2026-66370

NVD: 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... NVD: 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. NVD: Neither attribute receives a scheme check, so an absolute cross-origin URL survives sanitizing.

CVSS
4.8 Severity
MEDIUM EPSS
0.0023 (14) KEV
-

Source-published summary

NVD: 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... NVD: 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. NVD: Neither attribute receives a scheme check, so an absolute cross-origin URL survives sanitizing.

Possible impact

Source describes remote exposure. Possible impact: This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for remote exposure.

Affected context

vendor/product: rrrene / htmlsanitizeex

Remediation / advisory

Remediation reference present; patch status requires confirmation in the linked advisory.

Why it matters

Source describes remote exposure. Possible impact: This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for remote exposure.; CVSS 4.8 (MEDIUM); EPSS percentile 14; not listed in KEV; Remediation reference present; patch status requires confirmation in the linked advisory; sources: NVD, OSV.

What to verify

Confirm affected product/version, vendor advisory, patch or mitigation, and exposure.

Exposure hint

remote exposure

Impact tags

remote exposure relevant

Urgency reasons

affected product presentvendor advisory presentrecent updateremediation reference present

Source-derived note

Summary derived from NVD / OSV description; unsafe procedural detail is not shown.

Redaction metadata

source summary used
True
fallback summary used
False
unsafe procedural detail present
false
raw source displayed
false
public summary redacted
true

Remediation handoff

Public-safe static handoff for human/Codex remediation planning. Scan, patch, external execution, and auto remediation are disabled.

Handoff JSON Handoff Markdown Safe Codex prompt

Safety note

This radar shows source-published defensive context only. Exploit procedures, exploit strings, scanner commands, and auto-remediation are not provided.

Official references