Vulnerability in Matthewwithanm Markdownify

CVE-2025-46656

python-markdownify (aka markdownify) before 0.14.1 allows large headline prefixes such as <h9999999> in addition to <h1> through <h6>. This causes memory consumption.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 2.9 (Low). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.002 (11.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 11.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-46656: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-46656?
CVE-2025-46656 is a low-severity vulnerability in Matthewwithanm Markdownify, classified under Improper Validation of Specified Quantity in Input. CVSS score: 2.9/10. Published 2025-04-26.
How severe is CVE-2025-46656?
Low severity. CVSS v3 base score is 2.9 out of 10.
Is CVE-2025-46656 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.