CVE-2025-56218Network attack vector

User-triggered command execution via preserved malicious hyperlinks

Published Oct 17, 2025 · Updated Oct 17, 2025

Unrestricted file upload in Ascertia SigningHub 8.6.8 allows remote authenticated users to deliver malicious links through converted PDFs. The file-upload function converts an attacker-supplied Excel document to PDF while preserving attacker-controlled hyperlinks without scanning their content or warning recipients. A recipient must click a preserved link; the technical advisory describes phishing and command triggering, but the CNA does not identify a direct server-side code-execution locus.

CVSS severity9.8
Critical
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in Ascertia SigningHub 8.6.8 allows remote authenticated users to deliver malicious links through converted PDFs. The file-upload function converts an attacker-supplied Excel document to PDF while preserving attacker-controlled hyperlinks without scanning their content or warning recipients. A recipient must click a preserved link; the technical advisory describes phishing and command triggering, but the CNA does not identify a direct server-side code-execution locus.

The record

CVE
CVE-2025-56218
Published
Oct 17, 2025
Updated
Oct 17, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 17, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1204.001User Execution: Malicious Link

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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