CVE-2026-96640
Publication date 21 October 2026
Last updated 14 November 2026
Ubuntu priority
Description
Pillow is a Python imaging library. From 5.1.0 until 13.0.0, PdfParser.linearize_page_tree() in src/PIL/PdfParser.py treats a PDF /Pages graph as a tree without tracking duplicate indirect references. When Image.save(..., format="PDF", append=True) processes an attacker-controlled existing PDF whose /Kids arrays repeatedly reference the same child /Pages node, Pillow expands the shared subtree as distinct pages. A compact malformed PDF can therefore create exponentially many page references and consume disproportionate CPU before the append completes. This issue is fixed in version 13.0.0.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| pillow | 26.10 stonking |
Fixed in 12.3.0-1ubuntu2
|
| 26.04 LTS resolute |
Fixed in 12.1.1-2ubuntu1.5
|
|
| 24.04 LTS noble |
Fixed in 10.2.0-1ubuntu1.5
|
|
| 22.04 LTS jammy |
Fixed in 9.0.1-1ubuntu0.7
|
|
| 20.04 LTS focal |
Fixed in 7.0.0-4ubuntu0.9+esm2
|
|
| 18.04 LTS bionic |
Fixed in 5.1.0-1ubuntu0.8+esm3
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty |
Not affected
|
|
| pillow-python2 | 26.10 stonking | Not in release |
| 26.04 LTS resolute | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal |
Needs evaluation
|
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CVSS version:
Base score
8.2 · High
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Base score
7.5 · High
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
Related Ubuntu Security Notices (USN)
- USN-9064-1
- Pillow vulnerabilities
- 12 November 2026