CVE-2026-102995 · GHSA-fp3h-c4fm-7vvf
pypdf: Possible large memory usage for large /ToUnicode streams (Follow-up 2)
- 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 6.18.1, a crafted PDF can place unusually large source-code or destination-string tokens in a font /ToUnicode mapping, causing pypdf/_cmap.py parse_bfchar to decode and retain oversized values during operations such as text extraction and consume excess…
- Affected
- pypdf (pip) < 6.18.1
- Fix
- Upgrade pypdf to 6.18.1 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-2026-102995: Possible large memory usage for large /ToUnicode streams (Follow-up 2) (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: 6.18.1 · 6.17.0 · 6.19.0 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 | < 6.18.1 | 6.18.1 |
References
- https://github.com/advisories/GHSA-fp3h-c4fm-7vvf
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-fp3h-c4fm-7vvf
- https://nvd.nist.gov/vuln/detail/CVE-2026-102995
- https://github.com/py-pdf/pypdf/pull/4071
- https://github.com/py-pdf/pypdf/commit/319d0b823ce2c311a2435e9fd93c13994d32bb51
- https://github.com/py-pdf/pypdf/releases/tag/6.18.1
- https://github.com/advisories/GHSA-fp3h-c4fm-7vvf
Original description
pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF can place unusually large source-code or destination-string tokens in a font /ToUnicode mapping, causing pypdf/_cmap.py parse_bfchar to decode and retain oversized values during operations such as text extraction and consume excessive memory. This is a second follow-up to earlier /ToUnicode resource-consumption fixes and is limited to the remaining token-length path. This issue is fixed in version 6.18.1.
Last activity 30 Sep 2026. Patch Forecast updates every hour.