CVE-2023-0435Public exploit

Local data exposure via query-string prototype pollution

Published Jan 22, 2023 · Updated Apr 2, 2025

Prototype pollution in pyLoad before 0.5.0b3.dev41 allows local users to inject properties into Object.prototype through the web UI. The bundled MooTools More parseQueryString function follows attacker-controlled proto or constructor[prototype] keys and assigns their values without blocking prototype paths. Local access is required; the published assessment supports limited data exposure, not data modification or service interruption.

CVSS severity4.0
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Prototype pollution in pyLoad before 0.5.0b3.dev41 allows local users to inject properties into Object.prototype through the web UI. The bundled MooTools More parseQueryString function follows attacker-controlled proto or constructor[prototype] keys and assigns their values without blocking prototype paths. Local access is required; the published assessment supports limited data exposure, not data modification or service interruption.

The record

CVE
CVE-2023-0435
Published
Jan 22, 2023
Updated
Apr 2, 2025
Vendor
pyLoad
Product
pyLoad
Classifications
CWE-1125
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 2, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <0.5.0b3.dev41

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

pyLoad · pyLoadversion=unspecified <0.5.0b3.dev41

Published CVSS scores

4.0CVE CNACVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
9.8GitHub Advisory DatabaseCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1125Excessive Attack Surface

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo