What is CVE-2025-25977?

CVE-2025-25977 is a critical-severity vulnerability in Canvg, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 9.8/10. Published 2025-03-10.

How severe is CVE-2025-25977?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Prototype Pollution in Canvg

CVE-2025-25977

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

Vulnerability class: Prototype Pollution

Published 2025-03-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.8th percentile), scored 2026-10-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Canvg

Weakness classification (CWE)

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

References

github.com/canvg/canvg/issues/1749 (Exploit, Issue Tracking)

Frequently asked questions

What is CVE-2025-25977?: CVE-2025-25977 is a critical-severity vulnerability in Canvg, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 9.8/10. Published 2025-03-10.
How severe is CVE-2025-25977?: Critical severity. CVSS v3 base score is 9.8 out of 10.