CVE-2026-103000 · GHSA-w23x-9jrw-r45c
pypdf: Possible large memory usage when retrieving alphabetical page labels
- Risk score
- 60/100
- CVSS
- 7.5 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 30 Sep 2026
Open in the live forecast Today's forecast
What to know
- What it is
- pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF can provide unusually large alphabetical page-label values that cause pypdf/_page_labels.py to generate strings beyond a reasonable page-label length when an application retrieves document page labels, consuming excessive memory an…
- Affected
- pypdf (pip) < 6.19.0
- Fix
- Upgrade pypdf to 6.19.0 or later.
- Exploitation
- No known exploitation
Story map
At a glance
pypdf: Amber, patch this week. pypdf is a free and open-source pure-python PDF library. Prior to 6.17.0, a crafted PDF can provide unusually large Roman page-label values that cause pypdf/_page_labels.py to generate excessively large numeral strings when an application retrieves document page labels, consuming large amounts of memory and potentiall…
The flaws
- CVE-2026-103000: Possible large memory usage when retrieving alphabetical page labels (CVSS 7.5 · EPSS 0%)
- CVE-2026-102993: Possible large memory usage when retrieving Roman page labels (CVSS 7.5 · EPSS 0%)
- CVE-2026-102999: Possible long runtimes with large amount of embedded files (CVSS 7.5 · EPSS 0%)
- CVE-2026-102998: Possible long runtimes when generating appearance streams (CVSS 7.5 · EPSS 0%)
The fix
Upgrade pypdf: 6.19.0 · 6.17.0 or later on your release line
Who is exposed: pypdf (pip) < 6.17.0
Where it stands
- No known exploitation
Connects to
- Same weakness: Denial of service (CWE-400). 250 other warnings in 30 days
- Same product: Earlier pypdf warnings. 4 in the last 90 days
Why it is Amber
- CVSS 7.5 high
- Remotely exploitable without logging in
- On your watchlist: PyPI
Affected packages
| Package | Ecosystem | Vulnerable | Fixed in |
|---|---|---|---|
| pypdf | pip | < 6.19.0 | 6.19.0 |
References
- https://github.com/advisories/GHSA-w23x-9jrw-r45c
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-w23x-9jrw-r45c
- https://nvd.nist.gov/vuln/detail/CVE-2026-103000
- https://github.com/py-pdf/pypdf/pull/4096
- https://github.com/py-pdf/pypdf/commit/0d8b5a8832cde1ba308b5c27567b879b7b7eed4a
- https://github.com/py-pdf/pypdf/releases/tag/6.19.0
- https://github.com/advisories/GHSA-w23x-9jrw-r45c
Original description
pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF can provide unusually large alphabetical page-label values that cause pypdf/_page_labels.py to generate strings beyond a reasonable page-label length when an application retrieves document page labels, consuming excessive memory and potentially making the application unavailable. This issue is fixed in version 6.19.0.
Last activity 30 Sep 2026. Patch Forecast updates every hour.