CVE-2026-112900

Summary

PIL.EpsImagePlugin.Ghostscript() builds the Ghostscript command line using the input file path (fp.name) without sanitization, placing it at -f <infile>. A filename beginning with - is interpreted by Ghostscript as an option, giving command-line argument injection; chainable to RCE (see Impact). Reproduces with Pillow's default invocation (with -dSAFER enabled).

Details

Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer.

Type

CWE-88 (Argument Injection) (→ CWE-78 (OS Command Injection) optionally, with attacker controlled text file)

Vulnerable Codes

infile_temp = None
if hasattr(fp, "name") and os.path.exists(fp.name):
    infile = fp.name                      # user-controlled path used as-is, without validation
else:
    in_fd, infile_temp = tempfile.mkstemp()
    os.close(in_fd)
    infile = infile_temp
    # ... (copy fp into a temporary file)

# Build Ghostscript command
command = [
    gs_binary,
    "-q",
    f"-g{width:d}x{height:d}",
    f"-r{res_x:f}x{res_y:f}",
    "-dBATCH",
    "-dNOPAUSE",
    "-dSAFER",                            # default sandbox — does NOT stop this injection
    f"-sDEVICE={device}",
    f"-sOutputFile={outfile}",
    "-c",
    f"{-bbox[0]} {-bbox[1]} translate",
    "-f",
    infile,                               # injected here: inserted into argv with no check for
                                          # option prefixes (-, --) or Ghostscript's @-file token
                                          # => argument injection (CWE-88)
    "-c",
    "showpage",
]
# ...
subprocess.check_call(command, startupinfo=startupinfo)   # spawns Ghostscript

Root cause.

When rendering an EPS image, PIL.EpsImagePlugin.Ghostscript() constructs the Ghostscript command line using the input file path (fp.name) and places it directly at the -f <infile> position of the argument list. This path is user-controllable, yet Pillow performs no validation or neutralization of tokens that Ghostscript treats specially during command-line argument parsing — in particular a leading - or -- (which Ghostscript interprets as an option rather than a filename) and a leading @ (Ghostscript's argument-file syntax, which causes it to read additional command-line arguments from the named file). Because the filename is neither normalized (e.g., forced to an absolute path or prefixed with ./) nor checked against these prefixes before being handed to the subprocess, an attacker who controls the filename passed to Image.open() can inject arbitrary Ghostscript command-line arguments. This is a classic argument-injection flaw (CWE-88), and it is not mitigated by Pillow's default -dSAFER setting.

Affected

• Pillow: tested on 12.3.0 (latest); vulnerable code is long-standing and appears to affect all current versions (main included).
• Component: src/PIL/EpsImagePlugin.py, Ghostscript() — infile = fp.name, and the command list entry "-f", infile.

Suggested fix

Normalize the filename to an absolute path before it is passed to Ghostscript, so it can never be parsed as an option (-/--) or as an argument-file token (@):

    if hasattr(fp, "name") and os.path.exists(fp.name):
        infile = os.path.abspath(fp.name)   # was: infile = fp.name

os.path.abspath() guarantees the path starts with a path separator (or a drive letter on Windows), so a leading - or @ can no longer reach Ghostscript's argument parser. The else branch already builds a safe tempfile.mkstemp() path and needs no change.

PoC

dockerfile, Default run shows the argument-injection demo (poc.py); for the RCE PoC run python3 poc-rce.py.

FROM ubuntu:24.04

RUN apt update
RUN apt install -y --no-install-recommends python3 python3-venv ghostscript ca-certificates
RUN rm -rf /var/lib/apt/lists/*
RUN python3 -m venv /venv && /venv/bin/pip install --upgrade pip Pillow==12.3.0
ENV…

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• pillow: Pillow: Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO (CVE-2026-112393)

• pillow: Pillow: Heap buffer overflow in FlashPix (FPX) JPEG decoding leads to code execution (CVE-2026-112398)

• pillow: Pillow: Argument Injection in Ghostscript call, potentially leading into RCE (CVE-2026-112900)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Pillow is a Python imaging library. From 2.6.0 until 13.0.0, Pillow is vulnerable to argument injection when invoking Ghostscript for EPS input. EpsImagePlugin.Ghostscript passes a caller-controlled input filename after -f without converting it to a safe absolute path, so a name beginning with a hyphen can be interpreted as a Ghostscript option. An attacker who controls the filename can inject Ghostscript arguments. Arbitrary command execution specifically requires a leading @ argument-file filename and control of the referenced text file containing additional Ghostscript arguments; the reported chain reproduces with the default -dSAFER invocation. This issue is fixed in version 13.0.0.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• pillow: Pillow: Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO (CVE-2026-112393)
• pillow: Pillow: Heap buffer overflow in FlashPix (FPX) JPEG decoding leads to code execution (CVE-2026-112398)
• pillow: Pillow: Argument Injection in Ghostscript call, potentially leading into RCE (CVE-2026-112900)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Pillow is a Python imaging library. From 2.6.0 until 13.0.0, Pillow is vulnerable to argument injection when invoking Ghostscript for EPS input. EpsImagePlugin.Ghostscript passes a caller-controlled input filename after -f without converting it to a safe absolute path, so a name beginning with a hyphen can be interpreted as a Ghostscript option. An attacker who controls the filename can inject Ghostscript arguments. Arbitrary command execution specifically requires a leading @ argument-file filename and control of the referenced text file containing additional Ghostscript arguments; the reported chain reproduces with the default -dSAFER invocation. This issue is fixed in version 13.0.0.

TuxCare rebuilt pillow to address 10 CVEs. Fixed in 11.3.0.post8+tuxcare.

TuxCare rebuilt pillow to address 10 CVEs. Fixed in 11.2.1.post10+tuxcare.

TuxCare rebuilt pillow to address 10 CVEs. Fixed in 10.4.0.post12+tuxcare.

TuxCare rebuilt pillow to address 9 CVEs. Fixed in 9.5.0.post10+tuxcare.

TuxCare rebuilt pillow to address 9 CVEs. Fixed in 9.4.0.post11+tuxcare.

TuxCare rebuilt pillow to address 9 CVEs. Fixed in 8.4.0.post11+tuxcare.

These are all security issues fixed in the python313-Pillow-13.0.0-1.1 package on the GA media of openSUSE Tumbleweed.

Root has patched CVE-2026-112900 in the pillow package for Root:PyPI. Multiple fixed versions available.

This update for python-Pillow fixes the following issues:

• CVE-2026-96636: decompression-bomb protection bypass via multi-frame seek() in MPO and DCX (bsc#1286802).
• CVE-2026-96637: decompression bomb check bypass in SpiderImagePlugin.seek() leads to unbounded allocation DoS (bsc#1286801).
• CVE-2026-96640: PDF append accepts malformed shared page-tree DAG, which can cause resource exhaustion (bsc#1286798).
• CVE-2026-96641: reachable undefined behavior in native integer operations can lead to denial of service or logic integrity compromise (bsc#1286797).
• CVE-2026-96642: TarIO negative size field causes infinite CPU-spin loop (bsc#1286796).
• CVE-2026-112390: Denial of Service via infinite loop during crafted MIC image parsing (bsc#1286256).
• CVE-2026-112391: Denial of Service via unbounded recursion in PDF parser (bsc#1286273).
• CVE-2026-112392: Denial of Service via zero-size images in rank filters (bsc#1286287).
• CVE-2026-112393: heap buffer overflow and stale-heap disclosure in _tiffWriteProc when saving compressed TIFF data (bsc#1286325).
• CVE-2026-112394: P;2L and P;4L decoders may read 1 to 3 bytes past the passed buffer size (bsc#1286311).
• CVE-2026-112397: out-of-bounds access in _imagingmorph on a zero-width image (bsc#1286314).
• CVE-2026-112398: heap buffer overflow in FPX JPEG decoding can lead to code execution (bsc#1286406).
• CVE-2026-112399: Denial of service via crafted APNG image (bsc#1286368).
• CVE-2026-112400: Denial of Service via memory exhaustion from crafted GIF image (bsc#1286370).
• CVE-2026-112401: Denial of Service via crafted GIF comments (bsc#1286372).
• CVE-2026-112402: Denial of service via double free during image transformation (bsc#1286381).
• CVE-2026-112403: heap buffer overflow in ImagingJpegDecode allows for code execution (bsc#1286405).
• CVE-2026-112405: NULL pointer dereference in Image.merge via an unvalidated band 0 (bsc#1286404).
• CVE-2026-112406: infinite loop in PdfParser.rewrite_pages on page tree Parent cycle (bsc#1286403).
• CVE-2026-112891: quadratic GIF comment copying during save (bsc#1286402).
• CVE-2026-112892: MSP RLE decoder expands a tiny file into unbounded memory (bsc#1286401).
• CVE-2026-112894: Denial of Service via crafted multi-frame image conversion (bsc#1286408).
• CVE-2026-112895: Denial of service via crafted PDF during append operations (bsc#1286411).
• CVE-2026-112896: TIFF encoder ColorMap plane-size mismatch causes a heap out-of-bounds read (bsc#1286400).
• CVE-2026-112897: TiffDecode returns uninitialized memory as pixels for short JPEG strips (bsc#1286398).
• CVE-2026-112899: EPS load(scale) lets Ghostscript render past the decompression bomb limit (bsc#1286489).
• CVE-2026-112900: argument Injection in Ghostscript call can lead to remote code execution (bsc#1286397).
• CVE-2026-112901: ReDoS in XbmImagePlugin can be triggered by 512-byte file (bsc#1286396).
• CVE-2026-112902: memory disclosure and segfault in libtiff encoder via crafted TIFF tags (bsc#1286804).