CVE-2026-112399
8.7HighPublished 19 Oct 2026 · NVD status: Received · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Impact
- High impact on availability
- Weakness
- CWE-789
Impact
Remote attackers can crash your service via memory exhaustion by submitting a crafted APNG image. They need network access to any endpoint that calls Image.open() on user-uploaded files, with no authentication or frame loading required.
Root cause
Pillow allocates the full canvas size for an APNG disposal background inside Image.open() before enforcing decompression-bomb limits.
Affected systems
Pillow 8.1.0 through 12.x (before 13.0.0)
CVSS v4.0 · 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/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
Fix & remediation
Upgrade to Pillow 13.0.0 or later. If upgrading must wait, block or reject APNG uploads at your ingress boundary.
$ pip install --upgrade 'pillow>=13.0.0'AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
Pillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow can allocate an APNG disposal background at the full canvas size before applying the decompression-bomb check. A crafted APNG with a small first frame, a very large declared canvas, and background disposal or first-frame OP_PREVIOUS reaches PngImageFile._seek while Image.open() positions frame zero. The full-canvas allocation occurs inside Image.open() without requiring pixel loading or frame iteration. This can exhaust memory and deny service. This issue is fixed in version 13.0.0.