Uncontrolled Memory Allocation in Pillow - CVE-2026-55380

Vulnerability identifier: #VU136857

CSH Severity: Medium

CVSS v4: 8.7 [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]

CVE-ID: CVE-2026-55380

CWE-ID: CWE-789

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to memory allocation with excessive size value in GdImageFile._open() and the subsequent image loading path when processing a crafted .gd image through PIL.GdImageFile.open(fp) and calling load(). A remote attacker can supply a specially crafted .gd file with oversized dimensions to cause a denial of service.

A 1037-byte header-only file is sufficient to trigger an attempted allocation of approximately 4.3 GB.

Pillow
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
Red Hat Enterprise Linux for IBM z Systems
Anolis OS
Red Hat CodeReady Linux Builder for IBM z Systems
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Python 3 Module
SUSE Package Hub 15
openSUSE Leap
openEuler
Fedora
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
python-pillow (Red Hat package)
python3-pillow-tk
python3-pillow-doc
python3-pillow-devel
python3-pillow
python3-Pillow-tk
python3-Pillow-tk-debuginfo
python3-Pillow
python-Pillow-debugsource
python3-Pillow-debuginfo
python-Pillow-debuginfo
python3-pillow-help
python-pillow
python-pillow-debuginfo
python-pillow-debugsource
python3-pillow-qt
python311-Pillow-tk-debuginfo
python311-Pillow
python311-Pillow-debuginfo
python311-Pillow-tk

Install security update from vendor's website.

Pillow - update to 12.3.0
python-pillow (Red Hat package) - addressed in versions 5.1.1-15.el8_4.2, 5.1.1-20.el8_6, 5.1.1-20.el8_8, 5.1.1-22.el8_10
python3-pillow-tk - addressed in versions 5.1.1-22, 12.2.0-2
python3-pillow-doc - addressed in versions 5.1.1-22, 12.2.0-2
python3-pillow-devel - addressed in versions 5.1.1-22, 12.2.0-2
python3-pillow - addressed in versions 5.1.1-22, 12.2.0-2
python3-Pillow-tk - update to 7.2.0-150300.3.27.1
python3-Pillow-tk-debuginfo - update to 7.2.0-150300.3.27.1
python3-Pillow - update to 7.2.0-150300.3.27.1
python-Pillow-debugsource - addressed in versions 7.2.0-150300.3.27.1, 9.5.0-150400.5.25.1
python3-Pillow-debuginfo - update to 7.2.0-150300.3.27.1
python-Pillow-debuginfo - addressed in versions 7.2.0-150300.3.27.1, 9.5.0-150400.5.25.1
python3-pillow-tk - addressed in versions 9.0.1-12, 10.3.0-8
python3-pillow-help - addressed in versions 9.0.1-12, 10.3.0-8
python-pillow - addressed in versions 9.0.1-12, 10.3.0-8
python-pillow-debuginfo - addressed in versions 9.0.1-12, 10.3.0-8
python-pillow-debugsource - addressed in versions 9.0.1-12, 10.3.0-8
python3-pillow - addressed in versions 9.0.1-12, 10.3.0-8
python3-pillow-devel - addressed in versions 9.0.1-12, 10.3.0-8
python3-pillow-qt - addressed in versions 9.0.1-12, 10.3.0-8
python311-Pillow-tk-debuginfo - update to 9.5.0-150400.5.25.1
python311-Pillow - update to 9.5.0-150400.5.25.1
python311-Pillow-debuginfo - update to 9.5.0-150400.5.25.1
python311-Pillow-tk - update to 9.5.0-150400.5.25.1
python-pillow - addressed in versions 11.3.0-9.fc43, 11.3.0-10.fc43, 12.3.0-1.fc44
python3-pillow-qt - update to 12.2.0-2

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-phj9-mv4w-65pm

• Multiple vulnerabilities in Pillow
• Fedora 43 update for python-pillow
• Fedora 44 update for python-pillow
• SUSE update for python-Pillow
• Red Hat Enterprise Linux 8 update for python-pillow
• Anolis OS update for python-pillow
• Anolis OS update for python-pillow
• Fedora 43 update for python-pillow
• openEuler 24.03 LTS SP4 update for python-pillow
• openEuler 24.03 LTS SP3 update for python-pillow
• openEuler 24.03 LTS SP1 update for python-pillow
• openEuler 22.03 LTS SP4 update for python-pillow
• openEuler 20.03 LTS SP4 update for python-pillow
• SUSE update for python-Pillow
• Red Hat Enterprise Linux 8 update for python-pillow
• Red Hat Enterprise Linux 8 update for python-pillow
• Red Hat Enterprise Linux 8 update for python-pillow