Allocation of Resources Without Limits or Throttling in Pillow - CVE-2026-59204
Published: July 7, 2026
Vulnerability identifier: #VU137007
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-59204
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Alex Clark and Contributors
Affected software:
Pillow
Pillow
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper memory allocation in the JPEG2000 tiled decoder in src/libImaging/Jpeg2KDecode.c when parsing a crafted tiled JPEG2000 image during decoding. A remote attacker can supply a specially crafted tiled JPEG2000 file to cause a denial of service.
The issue occurs because total_component_width is accumulated across tiles and then used to calculate tile_bytes, which can grow the scratch buffer to roughly the decompressed size of the full image.
How to mitigate CVE-2026-59204
Install security update from vendor's website.