CVE-2025-56648Public exploitNetwork attack vector

Source-code disclosure via wildcard CORS response

Published Sep 17, 2025 · Updated Sep 17, 2025

Origin validation failure in Parcel 1.6.1 through 2.16.3 allows remote attackers to read development-server responses through a browser. Server.js sets Access-Control-Allow-Origin to a wildcard, permitting scripts from an untrusted website to read files served from localhost. Exploitation requires a developer to visit the malicious website while the development server is running, exposing served source code and generated bundles.

CVSS severity6.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Origin validation failure in Parcel 1.6.1 through 2.16.3 allows remote attackers to read development-server responses through a browser. Server.js sets Access-Control-Allow-Origin to a wildcard, permitting scripts from an untrusted website to read files served from localhost. Exploitation requires a developer to visit the malicious website while the development server is running, exposing served source code and generated bundles.

The record

CVE
CVE-2025-56648
Published
Sep 17, 2025
Updated
Sep 17, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-346, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

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

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-346Origin Validation Error
T1189Drive-by Compromise

Public exploit references

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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