Description
Pillow is a Python imaging library. From 9.1.0 until 13.0.0, Pillow can disclose uninitialized stack memory when Image.quantize() uses an empty palette. ImagingPaletteCacheUpdate() leaves a local cache array uninitialized when the palette has zero entries, and the conversion path emits those bytes as output pixel indices. An attacker who controls the palette image can obtain stack contents from a returned PNG or GIF. This can disclose addresses and stack-canary data without an out-of-bounds access, memory corruption, or process crash. This issue is fixed in version 13.0.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| python-pillow | Pillow | >= 9.1.0, < 13.0.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | pillow | No fix yet | — |
| Debian 13 | pillow | No fix yet | — |
| Debian 12 | pillow | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | pillow | 12.3.0-1ubuntu2 | USN-9064-1 |
| Ubuntu 26.04 LTS | pillow | 12.1.1-2ubuntu1.5 | USN-9064-1 |
| Ubuntu 24.04 LTS | pillow | 10.2.0-1ubuntu1.5 | USN-9064-1 |
| Ubuntu 22.04 LTS | pillow | 9.0.1-1ubuntu0.7 | USN-9064-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | pillow | 7.0.0-4ubuntu0.9+esm2 | USN-9064-1 |
| Ubuntu Pro 20.04 LTS | pillow-python2 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | pillow | 5.1.0-1ubuntu0.8+esm3 | USN-9064-1 |
| Ubuntu Pro 16.04 LTS | pillow | 3.1.2-0ubuntu1.6+esm4 | USN-9064-1 |
| Ubuntu Pro 14.04 LTS | pillow | 2.3.0-1ubuntu3.4+esm6 | USN-9064-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
| SLES 15 SP5 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
| SLES 15 SP4 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
| SLES 3 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | python-Pillow | 11.3.0-160000.9.1 | SUSE-SU-2026:24656-1 |
| SLES for SAP 15 SP6 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
| SLES for SAP 15 SP5 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
| SLES for SAP 15 SP4 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
| SLES 16.0 | python-Pillow | 11.3.0-160000.9.1 | SUSE-SU-2026:24656-1 |
| SLE HPC 15 SP5 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
| SLE HPC 15 SP4 | python-Pillow | 9.5.0-150400.5.28.1 | SUSE-SU-2026:5194-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-Pillow | 13.0.0-1.1 | openSUSE-SU-2026:12230-1 |
| openSUSE Leap 16.0 | python-Pillow | 11.3.0-160000.9.1 | openSUSE-SU-2026:22246-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | open-webui | 0.12.3-r6 | — |
| Wolfi rolling | py3.10-pillow | No fix yet | — |
| Wolfi rolling | py3.11-pillow +2 | 13.0.0-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | pillow | >= 9.1.0, < 13.0.0 | 13.0.0 | GHSA-rfgq-q3w2-pmv2 |
Advisories 5
- USN-9064-1 pillow vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- SUSE-SU-2026:24656-1 Security update for python-Pillow SUSE / openSUSE Security Updates · Nov 12, 2026
- SUSE-SU-2026:5194-1 Security update for python-Pillow SUSE / openSUSE Security Updates · Nov 12, 2026
- openSUSE-SU-2026:22246-1 Security update for python-Pillow SUSE / openSUSE Security Updates · Nov 11, 2026
- openSUSE-SU-2026:12230-1 python313-Pillow-13.0.0-1.1 on GA media SUSE / openSUSE Security Updates · Oct 23, 2026