Description
Pillow is a Python imaging library. From 5.3.0 until 13.0.0, Pillow can return uninitialized memory as pixels when libtiff performs a short decode of JPEG-compressed or Group 4 fax TIFF data. The _decodeStrip and _decodeTile buffers can be larger than the bytes written by libtiff, but Pillow converts the expected rows without clearing the unwritten tail. The tile path is affected from 5.3.0 and the strip path from 6.0.0. An attacker can supply a crafted TIFF to an application that loads and returns or re-encodes its pixels. This can disclose stale heap contents without memory corruption or a process crash. This issue is fixed in version 13.0.0.
Affected products
python: pillow
References4
- github.com/python-pillow/Pillow/security/advisories/GHSA-q45j-5… ExploitPatchVendor Advisory
- github.com/python-pillow/Pillow/security/advisories/GHSA-q45j-5… ExploitPatchVendor Advisory
- github.com/python-pillow/Pillow/commit/1d4773e6cea0c4a2814e6d4c… Patch
- github.com/python-pillow/Pillow/releases/tag/13.0.0 Release Notes
Metrics
- CVSS 3.1
-
6.2
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 4.0
-
8.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 42 · as of 10 November 2026
- CWE
- CWE-908
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.