Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-112406Pillow: Infinite loop in PdfParser.rewrite_pages on page tree Parent cycle
High 8.7
In plain English
A high-severity infinite loop in Pillow from python-pillow. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow can enter an infinite loop while rewriting PDF pages. PdfParser.rewrite_pages() follows Parent relationships without detecting a cycle in the page tree. An attacker can supply a cyclic PDF to an application that appends an image to that PDF. This can hold the worker at full CPU and deny service. This issue is fixed in version 13.0.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | python3-pillow | 5.1.1-33.el8_10 | ALSA-2026:92639 |
| AlmaLinux:8 | python3-pillow-devel | 5.1.1-33.el8_10 | ALSA-2026:92639 |
| AlmaLinux:8 | python3-pillow-doc | 5.1.1-33.el8_10 | ALSA-2026:92639 |
| AlmaLinux:8 | python3-pillow-tk | 5.1.1-33.el8_10 | ALSA-2026:92639 |
| Debian:12 | pillow | no fix listed | DEBIAN-CVE-2026-112406 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-112406 |
| Debian:14 | pillow | no fix listed | DEBIAN-CVE-2026-112406 |
| PyPI | pillow | 13.0.0 | GHSA-f2g6-542v-9j58 |
| Rocky Linux:8 | python-pillow | 0:5.1.1-33.el8_10 | RLSA-2026:92639 |
| Ubuntu:22.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112406 |
| Ubuntu:24.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112406 |
| Ubuntu:26.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112406 |
| Ubuntu:26.10 | pillow | no fix listed | UBUNTU-CVE-2026-112406 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | >= 5.1.0, < 13.0.0 |
Weakness: CWE-835 · Vector: 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