Amazon Linux 2023 Security Advisory: ALAS2023-2026-3411
Advisory Released Date: 2026-11-09
Advisory Updated Date: 2026-11-09
FAQs regarding Amazon Linux ALAS/CVE Severity
Pillow is a Python imaging library. From 7.2.0 until 13.0.0, Pillow can enter an infinite loop while determining the frame count of a MIC image. MicImageFile inherits TIFF frame traversal, but MicImageFile.tell reports the OLE stream index and its seek() resets TIFF frame state, so an embedded TIFF with at least three IFDs never advances. When an application with olefile installed reads n_frames or saves all frames from a crafted MIC file, the non-advancing traversal can hold a worker at full CPU indefinitely. This issue is fixed in version 13.0.0. (CVE-2026-112390)
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's rank-based filters can dereference invalid image storage for a zero-size image. ImagingExpand() allocates a non-empty output and then faults while replicating edges by reading the first pixel from empty input storage; ImagingRankFilter is never reached. An attacker can supply or cause creation of a zero-size image to an application that applies a rank, median, minimum, or maximum filter. This causes a native process crash. This issue is fixed in version 13.0.0. (CVE-2026-112392)
Pillow is a Python imaging library. From 2.0.0 until 13.0.0, Pillow has a heap buffer overflow and stale-heap disclosure in _tiffWriteProc when saving compressed TIFF data through libtiff to a target without a usable fileno(), such as BytesIO. The callback sizes its allocation from the prior buffer size instead of the current write position, allowing an attacker-controlled out-of-line TIFF tag or retained ICC profile to be copied beyond the allocation after libtiff seeks forward. This overflow can crash the process and may allow code execution. Independently, unwritten alignment gaps in compressed TIFF output larger than 64 KiB can disclose stale heap bytes without a crafted tag. File paths and targets with real file descriptors are unaffected. This issue is fixed in version 13.0.0. (CVE-2026-112393)
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's FlashPix JPEG-tile decoder can write decoded scanlines beyond the allocated tile buffer. FlashPix (FPX) JPEG decoding selects raw mode LA with two bytes per pixel, while an unrecognized JPEG mode can be decoded as JCS_UNKNOWN with four components, causing ImagingJpegDecode to write four-component scanlines into the two-byte tile buffer. An attacker can supply a crafted OLE2 FlashPix file to an application with the optional olefile dependency installed that opens or thumbnails untrusted input. This can corrupt heap memory and may allow arbitrary code execution. This issue is fixed in version 13.0.0. (CVE-2026-112398)
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. (CVE-2026-112399)
Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow takes quadratic time to reserve PDF object identifiers when saving many frames with save_all enabled. PdfParser.next_object_id() repeatedly rebuilds and scans all previously reserved identifiers for every object. An attacker can supply a multi-frame image, including a small APNG with a large declared frame count, to an application that converts it to a multipage PDF. This can consume excessive CPU and deny service. This issue is fixed in version 13.0.0. (CVE-2026-112894)
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's TIFF encoder can read beyond a ColorMap buffer when retained TIFF metadata has a plane size inconsistent with BitsPerSample. A small TIFF can be opened normally and then retain a crafted ColorMap that is reused when the image is saved. An application that re-encodes the attacker's TIFF with libtiff can trigger the out-of-bounds read. This can disclose heap memory in the output or crash the process. This issue is fixed in version 13.0.0. (CVE-2026-112896)
Pillow is a Python imaging library. From 5.3.0 until 13.0.0, Pillow can return uninitialized memory as pixels when libtiff performs a short decode of JPEG-compressed or Group 4 fax TIFF data. The _decodeStrip and _decodeTile buffers can be larger than the bytes written by libtiff, but Pillow converts the expected rows without clearing the unwritten tail. The tile path is affected from 5.3.0 and the strip path from 6.0.0. An attacker can supply a crafted TIFF to an application that loads and returns or re-encodes its pixels. This can disclose stale heap contents without memory corruption or a process crash. This issue is fixed in version 13.0.0. (CVE-2026-112897)
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. (CVE-2026-112900)
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's XBM header parser is vulnerable to regular-expression denial of service. In XbmImageFile._open, when an application calls Image.open() on a small crafted XBM file, XbmImagePlugin applies a backtracking expression to the attacker-controlled header before image dimensions are accepted, stalling a worker for minutes and denying service. This issue is fixed in version 13.0.0. (CVE-2026-112901)
Pillow is a Python imaging library. From 9.4.0 until 13.0.0, ImagingJpegEncode() in src/libImaging/JpegEncode.c can call jpeg_write_marker() for a JPEG COM comment when an ICC profile has exactly filled the 65536-byte encoder buffer. libjpeg writes one byte before checking the exhausted free_in_buffer counter, which then wraps and permits the attacker-controlled comment and subsequent compressed image data to overwrite adjacent heap memory. Re-saving an untrusted image as JPEG while preserving its ICC profile and forwarded comment can crash the process and may enable code execution in suitable runtime and heap layouts. This issue is fixed in version 13.0.0. (CVE-2026-96778)
Affected Packages:
python-pillow
Issue Correction:
Run dnf update python-pillow --releasever 2023.12.20261109 or dnf update --advisory ALAS2023-2026-3411 --releasever 2023.12.20261109 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
aarch64:
python3-pillow-debuginfo-9.4.0-2.amzn2023.0.12.aarch64
python3-pillow-tk-9.4.0-2.amzn2023.0.12.aarch64
python-pillow-debugsource-9.4.0-2.amzn2023.0.12.aarch64
python-pillow-debuginfo-9.4.0-2.amzn2023.0.12.aarch64
python3-pillow-tk-debuginfo-9.4.0-2.amzn2023.0.12.aarch64
python3-pillow-devel-9.4.0-2.amzn2023.0.12.aarch64
python3-pillow-9.4.0-2.amzn2023.0.12.aarch64
src:
python-pillow-9.4.0-2.amzn2023.0.12.src
x86_64:
python3-pillow-debuginfo-9.4.0-2.amzn2023.0.12.x86_64
python3-pillow-tk-debuginfo-9.4.0-2.amzn2023.0.12.x86_64
python-pillow-debugsource-9.4.0-2.amzn2023.0.12.x86_64
python3-pillow-9.4.0-2.amzn2023.0.12.x86_64
python-pillow-debuginfo-9.4.0-2.amzn2023.0.12.x86_64
python3-pillow-devel-9.4.0-2.amzn2023.0.12.x86_64
python3-pillow-tk-9.4.0-2.amzn2023.0.12.x86_64