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GHSA-cfh3-3jmp-rvhc BIT-pillow-2026-25990 CVE-2026-25990 PYSEC-2026-2249

Pillow affected by out-of-bounds write when loading PSD images

High PyPI
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.41%
Chance of exploitation in the next 30 days. Higher than 35.16% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-787 Out-of-bounds Write
Fix
12.1.1
Upgrade pillow to this version or later

Description

Impact

An out-of-bounds write may be triggered when loading a specially crafted PSD image. Pillow >= 10.3.0 users are affected.

Patches

Pillow 12.1.1 will be released shortly with a fix for this.

Workarounds

Image.open() has a formats parameter that can be used to prevent PSD images from being opened.

References

Pillow 12.1.1 will add release notes at https://pillow.readthedocs.io/en/stable/releasenotes/index.html

Affected versions

PyPI

PackageVulnerableFixed in
pillow
>= 10.3.0, < 12.1.1
12.1.1

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

pillow PyPI → 12.1.1

pip
pip install --upgrade "pillow>=12.1.1"
poetry
poetry add "pillow>=12.1.1"
uv
uv add "pillow>=12.1.1"

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack vector
Local
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
High
Integrity (vulnerable system)
High
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Weakness

CWE-787: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How to prevent it
  • Requirements: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.
  • Operation, Build and Compilation: Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
  • Implementation: Consider adhering to the following rules when allocating and managing an application's memory: Double check that the buffer is as large as specified. When using functions that accept a number of bytes to copy, such as strncpy(), be aware that if the destination buffer size is equal to the source buffer size, it may not NULL-terminate the string. Check buffer boundaries if accessing the buffer in a loop and make sure there is no danger of writing past the allocated space. If necessary, truncate all input strings to a reasonable length before passing them to the copy and concatenation functions.
  • Operation, Build and Compilation: Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code. Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking. For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].
  • Operation: Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].
  • Implementation: Replace unbounded copy functions with analogous functions that support length arguments, such as strcpy with strncpy. Create these if they are not available.

References

Advisories

Fixes and patches

Issue reports

Packages

Other links

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
PYSEC-2023-175
Pillow versions before v10.0.1 bundled libwebp binaries in wheels that are vulnerable to CVE-2023-5129 (previously CVE-2023-4863).
High Known exploited Also affects pillow
GHSA-j7hp-h8jx-5ppr
libwebp: OOB write in BuildHuffmanTable
High Known exploited Also affects pillow
GHSA-78g4-xqwv-q3g8
Pillow: Bundled libopenjp2 2.5.4 in all wheels since 11.1.0 carries OSV-2025-219 heap-buffer-overflow write reachable from Image.open().load()
High Also affects pillow
GHSA-654x-cwwv-5j9c
Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT > 1
Medium Also affects pillow
GHSA-xvh5-g6gv-559v
Pillow: Memory disclosure and segfault in libtiff encoder via crafted TIFF tags
High Also affects pillow
GHSA-g7cr-3p24-7wf7
Pillow: Heap buffer overflow writing JPEG comment after ICC profile fills buffer
High Also affects pillow
GHSA-9v9v-9qvf-h2hj
Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)
High Also affects pillow
GHSA-g4qv-2jxx-769h
Pillow: PNG eXIf chunk makes EXIF parsing run in quadratic time
Medium Also affects pillow
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