CVE-2025-66019
pypdf manipulated LZWDecode streams can exhaust RAM
MEDIUM 6.6
At a glance
- Source
- NVD
- EPSS
- EPSS 0.39 % · percentile 33 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Deferred
Description
pypdf is a free and open-source pure-python PDF library. Prior to version 6.4.0, an attacker who uses this vulnerability can craft a PDF which leads to a memory usage of up to 1 GB per stream. This requires parsing the content stream of a page using the LZWDecode filter. This issue has been patched in version 6.4.0.
Weaknesses (CWE)
- CWE-400 — Uncontrolled Resource Consumption (DoS)
- CWE-409 — Improper Handling of Highly Compressed Data (Zip Bomb)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 6.6 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U | GitHub_M |
| CVSS 4.0 | MEDIUM 6.6 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-m449-cwjh-6pw7 — pypdf's LZWDecode streams be manipulated to exhaust RAM
- PYSEC-2026-1832 — pypdf's LZWDecode streams be manipulated to exhaust RAM
European references
- ENISA EUVD · EUVD-2025-199017
- GCVE · GCVE-0-2025-66019
CERT-FR advisories
- CERTFR-2026-AVI-0224 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| py-pdf · pypdf | affected < 6.4.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |