CVE-2026-102996

pypdf: Possible large memory usage when parsing font data

HIGH 8.7

At a glance

Source: NVD
EPSS: EPSS 0.34 % · percentile 27 (2026-10-28)
State: PUBLISHED
Published: 2026-09-30 20:03 UTC
Updated: 2026-09-30 20:48 UTC
Assigner: GitHub_M
NVD status: Analyzed

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF can provide a TrueType or Type1 simple font with an unusually large /Widths array, causing pypdf/_font.py Font._collect_tt_t1_character_widths to process entries beyond the 256 character codes meaningful for a simple font and consume excessive memory during operations such as text extraction. This issue is fixed in version 6.18.1.

Weaknesses (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

Scores

Version	Score	Vector	Scored by
CVSS 4.0	HIGH 8.7	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	GitHub_M
CVSS 4.0	HIGH 8.7	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:X/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)
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	NVD · nvd@nist.gov (Primary)

Advisories

GHSA-g9cg-prrw-2r8q — pypdf: Possible large memory usage when parsing font data
PYSEC-2026-4155 — pypdf: Possible large memory usage when parsing font data

European references

ENISA EUVD · EUVD-2026-90368
GCVE · GCVE-0-2026-102996

Affected configurations (NVD CPE)

cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:* < 6.18.1

Affected products

Product	Versions
py-pdf · pypdf	affected < 6.18.1

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
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