CVE-2025-25977Public exploitNetwork attack vector

Code execution via StyleElement prototype pollution

Published Mar 10, 2025 · Updated Mar 12, 2025

Prototype pollution in canvg 3.0.10 and earlier and 4.0.0 through 4.0.2 allows remote attackers to execute code via crafted CSS. The StyleElement constructor stores attacker-controlled CSS selectors in ordinary object-backed style maps, so a proto selector modifies the global prototype chain. Code execution requires a consuming application to pass untrusted CSS into StyleElement and later use polluted properties with sensitive APIs such as exec or eval.

CVSS severity9.8
Critical
EPSS probability0.71%
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 canvg 3.0.10 and earlier and 4.0.0 through 4.0.2 allows remote attackers to execute code via crafted CSS. The StyleElement constructor stores attacker-controlled CSS selectors in ordinary object-backed style maps, so a proto selector modifies the global prototype chain. Code execution requires a consuming application to pass untrusted CSS into StyleElement and later use polluted properties with sensitive APIs such as exec or eval.

The record

CVE
CVE-2025-25977
Published
Mar 10, 2025
Updated
Mar 12, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1321
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 12, 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

8.9GitHub Security Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

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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