CVE-2025-25977

canvg Prototype Pollution vulnerability

9.8 CriticalFix available

An issue in canvg v.4.0.2 allows an attacker to execute arbitrary code via the Constructor of the class StyleElement.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.71%Up 0.7 points since Mar 11, 2025

What each source reports

CVE List Score used 9.8

An issue in canvg v.4.0.2 allows an attacker to execute arbitrary code via the Constructor of the class StyleElement.

Record: CVE-2025-25977
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-1321
Updated: 2026-11-02

EUVDEUVD-2025-6266 9.8

An issue in canvg v.4.0.2 allows an attacker to execute arbitrary code via the Constructor of the class StyleElement.

Record: EUVD-2025-6266
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-v2mw-5mch-w8c5 8.9

canvg Prototype Pollution vulnerability

An issue in canvg prior to v.4.0.3 and v3.0.11 can lead to prototype pollution via the Constructor of the class StyleElement.

Record: GHSA-v2mw-5mch-w8c5
CVSS 4.0: 8.9 HighCVSS: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
Weakness: CWE-1321
Updated: 2026-11-02

NVD 9.8

An issue in canvg v.4.0.2 allows an attacker to execute arbitrary code via the Constructor of the class StyleElement.

Record: CVE-2025-25977
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-1321
Updated: 2026-11-02

OSV 9.8

An issue in canvg v.4.0.2 allows an attacker to execute arbitrary code via the Constructor of the class StyleElement.

Record: CVE-2025-25977
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2025-25977 9.8

An issue in canvg v.4.0.2 allows an attacker to execute arbitrary code via the Constructor of the class StyleElement.

Record: DEBIAN-CVE-2025-25977
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVGHSA-v2mw-5mch-w8c5 8.9

canvg Prototype Pollution vulnerability

An issue in canvg prior to v.4.0.3 and v3.0.11 can lead to prototype pollution via the Constructor of the class StyleElement.

Record: GHSA-v2mw-5mch-w8c5
CVSS 4.0: 8.9 HighCVSS: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
Weakness: CWE-1321
Updated: 2026-11-02

OSVUBUNTU-CVE-2025-25977 9.8

An issue in canvg v.4.0.2 allows an attacker to execute arbitrary code via the Constructor of the class StyleElement.

Record: UBUNTU-CVE-2025-25977
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

Affected products

canvg

Affected packages

Affected packages
Package	Affected	Fixed
`canvg` npm	4.0.0 up to 4.0.3	4.0.3
`canvg` npm	before 3.0.11	3.0.11
`znuny` Debian:12	All versions, plus listed versions 6.3.2-36.3.3-16.3.3-1~bpo11+16.3.4-16.3.4-1~bpo11+1 Show 44 moreShow less 6.4.2-16.4.2-1~bpo11+16.4.2-26.4.3-16.4.3-1~bpo11+16.4.4-16.4.5-16.4.5-1~bpo11+16.4.5-26.5.1-16.5.10-16.5.10-1~bpo12+16.5.11-16.5.11-1~bpo12+16.5.13-16.5.14-16.5.14-1~bpo12+16.5.15-16.5.15-26.5.15-2~bpo12+16.5.16-16.5.18-16.5.18-1~bpo13+16.5.19-16.5.20-16.5.21-16.5.22-16.5.22-1~bpo13+16.5.23-16.5.23-1~bpo13+16.5.24-16.5.24-1~bpo13+16.5.3-16.5.3-1~bpo12+16.5.4-16.5.4-1~bpo12+16.5.5-16.5.5-1~bpo12+16.5.6-16.5.6-1~bpo12+16.5.8-16.5.8-1~bpo12+16.5.9-16.5.9-1~bpo12+1	None known
`znuny` Debian:13	All versions, plus listed versions 6.3.2-36.3.3-16.3.3-1~bpo11+16.3.4-16.3.4-1~bpo11+1 Show 44 moreShow less 6.4.2-16.4.2-1~bpo11+16.4.2-26.4.3-16.4.3-1~bpo11+16.4.4-16.4.5-16.4.5-1~bpo11+16.4.5-26.5.1-16.5.10-16.5.10-1~bpo12+16.5.11-16.5.11-1~bpo12+16.5.13-16.5.14-16.5.14-1~bpo12+16.5.15-16.5.15-26.5.15-2~bpo12+16.5.16-16.5.18-16.5.18-1~bpo13+16.5.19-16.5.20-16.5.21-16.5.22-16.5.22-1~bpo13+16.5.23-16.5.23-1~bpo13+16.5.24-16.5.24-1~bpo13+16.5.3-16.5.3-1~bpo12+16.5.4-16.5.4-1~bpo12+16.5.5-16.5.5-1~bpo12+16.5.6-16.5.6-1~bpo12+16.5.8-16.5.8-1~bpo12+16.5.9-16.5.9-1~bpo12+1	None known
`znuny` Debian:14	before 6.5.24-1, plus listed versions 6.3.2-36.3.3-16.3.3-1~bpo11+16.3.4-16.3.4-1~bpo11+1 Show 43 moreShow less 6.4.2-16.4.2-1~bpo11+16.4.2-26.4.3-16.4.3-1~bpo11+16.4.4-16.4.5-16.4.5-1~bpo11+16.4.5-26.5.1-16.5.10-16.5.10-1~bpo12+16.5.11-16.5.11-1~bpo12+16.5.13-16.5.14-16.5.14-1~bpo12+16.5.15-16.5.15-26.5.15-2~bpo12+16.5.16-16.5.18-16.5.18-1~bpo13+16.5.19-16.5.20-16.5.21-16.5.22-16.5.22-1~bpo13+16.5.23-16.5.23-1~bpo13+16.5.24-1~bpo13+16.5.3-16.5.3-1~bpo12+16.5.4-16.5.4-1~bpo12+16.5.5-16.5.5-1~bpo12+16.5.6-16.5.6-1~bpo12+16.5.8-16.5.8-1~bpo12+16.5.9-16.5.9-1~bpo12+1	6.5.24-1
`otrs2` Ubuntu:16.04:LTS	All versions, plus listed versions 4.0.10-15.0.1-15.0.1-25.0.2-15.0.3-15.0.5-15.0.6-15.0.7-1	None known
`otrs2` Ubuntu:18.04:LTS	All versions, plus listed versions 5.0.23-15.0.24-16.0.1-16.0.2-16.0.3-16.0.4-16.0.5-1	None known
`otrs2` Ubuntu:20.04:LTS	All versions, plus listed versions 6.0.20-16.0.23-26.0.24-16.0.25-16.0.25-26.0.25-36.0.26-1	None known
`otrs2` Ubuntu:22.04:LTS	All versions, plus listed versions 6.0.32-66.1.2-16.2.1-16.2.2-2	None known
`znuny` Ubuntu:24.04:LTS	All versions, plus listed versions 6.5.3-16.5.4-16.5.5-16.5.6-1	None known
`znuny` Ubuntu:26.10	All versions, plus listed versions 6.5.18-16.5.20-16.5.21-16.5.22-16.5.23-1	None known
`znuny` Ubuntu:26.04:LTS	All versions, plus listed versions 6.5.15-26.5.18-1	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-25977 is a critical vulnerability (CVSS 9.8) in Canvg, published March 10, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.71%, the 53rd percentile. Fixed in canvg 4.0.3.

References

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