CVE-2023-30533Network attack vector

Prototype pollution via unsafe XML attribute assignment

Published Apr 24, 2023 · Updated Feb 4, 2025

Prototype pollution in SheetJS Community Edition 0.19.2 and earlier allows attackers to alter object prototypes through a crafted file. The parsexmltag and parsexmltagraw XML parsers assign attacker-controlled attribute names to ordinary objects without rejecting proto, constructor, or prototype keys. A workflow must read an attacker-supplied file; export-only workflows are unaffected, and downstream impact depends on how polluted properties are consumed.

CVSS severity7.8
High
EPSS probability0.99%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in SheetJS Community Edition 0.19.2 and earlier allows attackers to alter object prototypes through a crafted file. The parsexmltag and parsexmltagraw XML parsers assign attacker-controlled attribute names to ordinary objects without rejecting proto, constructor, or prototype keys. A workflow must read an attacker-supplied file; export-only workflows are unaffected, and downstream impact depends on how polluted properties are consumed.

The record

CVE
CVE-2023-30533
Published
Apr 24, 2023
Updated
Feb 4, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1321
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3SheetJSCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N
7.8GitHubCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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