Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-112895Pillow: Unbounded recursion parsing a PDF page tree or trailer chain (incomplete fix for CVE-2026-42310)
High 8.7
In plain English
A high-severity security flaw 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 49% 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 exhaust resources while parsing an existing PDF during an append operation. PdfParser follows page-tree child references without cycle or duplication tracking and follows previous-trailer chains with only an exact repeated-offset guard, so deep or cyclic page trees and long chains of unique trailer offsets can exhaust the Python stack. Repeated non-cyclic /Kids references can also cause super-linear CPU and memory use. An attacker can supply such a PDF to an application that calls Image.save with PDF append enabled. This can raise an uncaught RecursionError or consume excessive CPU and memory before output is written, causing denial of 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-2026-112895 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-112895 |
| Debian:14 | pillow | no fix listed | DEBIAN-CVE-2026-112895 |
| PyPI | pillow | 13.0.0 | GHSA-p4wg-p73j-c528 |
| 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-2026-112895 |
| Ubuntu:24.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112895 |
| Ubuntu:26.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112895 |
| Ubuntu:26.10 | pillow | no fix listed | UBUNTU-CVE-2026-112895 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | >= 5.1.0, < 13.0.0 |
Weakness: CWE-674 · 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