CVE-2026-23874

Summary

Stack overflow via infinite recursion in MSL (Magick Scripting Language) <write> command when writing to MSL format.

Version

• ImageMagick 7.x (tested on current main branch)
• Commit: HEAD
• Requires: libxml2 support (for MSL parsing)

Steps to Reproduce

Method 1: Using ImageMagick directly

magick MSL:recursive.msl out.png

Method 2: Using OSS-Fuzz reproduce

python3 infra/helper.py build_fuzzers imagemagick
python3 infra/helper.py reproduce imagemagick msl_fuzzer recursive.msl

Or run the fuzzer directly:

./msl_fuzzer recursive.msl

Expected Behavior

ImageMagick should handle recursive MSL references gracefully by detecting the loop and returning an error.

Actual Behavior

Stack overflow causes process crash:

AddressSanitizer:DEADLYSIGNAL
==PID==ERROR: AddressSanitizer: stack-overflow
    #0 MSLStartElement /src/imagemagick/coders/msl.c:7045
    #1 xmlParseStartTag /src/libxml2/parser.c
    #2 xmlParseChunk /src/libxml2/parser.c:11273
    #3 ProcessMSLScript /src/imagemagick/coders/msl.c:7405
    #4 WriteMSLImage /src/imagemagick/coders/msl.c:7867
    #5 WriteImage /src/imagemagick/MagickCore/constitute.c:1346
    #6 MSLStartElement /src/imagemagick/coders/msl.c:7045
    ... (infinite recursion, 287+ frames)

Root Cause Analysis

In coders/msl.c, the <write> command handler in MSLStartElement() (line ~7045) calls WriteImage(). When the output filename specifies MSL format (msl:filename), WriteMSLImage() is called, which parses the MSL file again via ProcessMSLScript().

If the MSL file references itself (directly or indirectly), this creates an infinite recursion loop:

MSLStartElement() → WriteImage() → WriteMSLImage() → ProcessMSLScript()
    → xmlParseChunk() → MSLStartElement() → ... (infinite loop)

Impact

• DoS: Guaranteed crash via stack exhaustion
• Affected: Any application using ImageMagick to process user-supplied MSL files

Additional Trigger Paths

The <read> command can also trigger recursion:

Indirect recursion is also possible (a.msl → b.msl → a.msl).

Fuzzer

This issue was discovered using a custom MSL fuzzer:

#include <cstdint>
#include <Magick++/Blob.h>
#include <Magick++/Image.h>
#include "utils.cc"

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
  if (IsInvalidSize(Size))
    return(0);
  try
  {
    const Magick::Blob blob(Data, Size);
    Magick::Image image;
    image.magick("MSL");
    image.fileName("MSL:");
    image.read(blob);
  }
  catch (Magick::Exception)
  {
  }
  return(0);
}

This issue was found by Team FuzzingBrain @ Texas A&M University

Summary

Stack overflow via infinite recursion in MSL (Magick Scripting Language) <write> command when writing to MSL format.

Version

• ImageMagick 7.x (tested on current main branch)
• Commit: HEAD
• Requires: libxml2 support (for MSL parsing)

Steps to Reproduce

Method 1: Using ImageMagick directly

magick MSL:recursive.msl out.png

Method 2: Using OSS-Fuzz reproduce

python3 infra/helper.py build_fuzzers imagemagick
python3 infra/helper.py reproduce imagemagick msl_fuzzer recursive.msl

Or run the fuzzer directly:

./msl_fuzzer recursive.msl

Expected Behavior

ImageMagick should handle recursive MSL references gracefully by detecting the loop and returning an error.

Actual Behavior

Stack overflow causes process crash:

AddressSanitizer:DEADLYSIGNAL
==PID==ERROR: AddressSanitizer: stack-overflow
    #0 MSLStartElement /src/imagemagick/coders/msl.c:7045
    #1 xmlParseStartTag /src/libxml2/parser.c
    #2 xmlParseChunk /src/libxml2/parser.c:11273
    #3 ProcessMSLScript /src/imagemagick/coders/msl.c:7405
    #4 WriteMSLImage /src/imagemagick/coders/msl.c:7867
    #5 WriteImage /src/imagemagick/MagickCore/constitute.c:1346
    #6 MSLStartElement /src/imagemagick/coders/msl.c:7045
    ... (infinite recursion, 287+ frames)

Root Cause Analysis

In coders/msl.c, the <write> command handler in MSLStartElement() (line ~7045) calls WriteImage(). When the output filename specifies MSL format (msl:filename), WriteMSLImage() is called, which parses the MSL file again via ProcessMSLScript().

If the MSL file references itself (directly or indirectly), this creates an infinite recursion loop:

MSLStartElement() → WriteImage() → WriteMSLImage() → ProcessMSLScript()
    → xmlParseChunk() → MSLStartElement() → ... (infinite loop)

Impact

• DoS: Guaranteed crash via stack exhaustion
• Affected: Any application using ImageMagick to process user-supplied MSL files

Additional Trigger Paths

The <read> command can also trigger recursion:

Indirect recursion is also possible (a.msl → b.msl → a.msl).

Fuzzer

This issue was discovered using a custom MSL fuzzer:

#include <cstdint>
#include <Magick++/Blob.h>
#include <Magick++/Image.h>
#include "utils.cc"

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
  if (IsInvalidSize(Size))
    return(0);
  try
  {
    const Magick::Blob blob(Data, Size);
    Magick::Image image;
    image.magick("MSL");
    image.fileName("MSL:");
    image.read(blob);
  }
  catch (Magick::Exception)
  {
  }
  return(0);
}

This issue was found by Team FuzzingBrain @ Texas A&M University

Use ImageMagick to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.

Security Fix(es):

ImageMagick contains an infinite recursion vulnerability in MSL script processing that can lead to stack overflow. The vulnerability exists in the ProcessMSLScript function, where attackers can craft malicious MSL scripts to trigger infinite recursion, ultimately causing stack overflow.(CVE-2026-23874)

ImageMagick is a widely used free and open-source software for image editing and manipulation. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability exists in the XBM image decoder (ReadXBMImage function). An attacker can exploit this by crafting a malicious XBM image file, causing controlled data to be written past the bounds of an allocated heap buffer during processing. Any operation that reads or identifies an image, such as common image upload and processing pipelines, can trigger this overflow, potentially leading to arbitrary code execution or application crash.(CVE-2026-23876)

ImageMagick is free and open-source software used for editing and manipulating digital images. Versions 14.10.1 and below have a NULL pointer dereference vulnerability in the MSL (Magick Scripting Language) parser when processing <comment> tags before images are loaded. This can lead to DoS attack due to assertion failure (debug builds) or NULL pointer dereference (release builds). This issue is fixed in version 14.10.2.(CVE-2026-23952)

Use ImageMagick to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.

Security Fix(es):

A vulnerability exists in ImageMagick's BilateralBlur functionality where an invalid pointer is released when memory allocation fails, potentially leading to application crashes or security risks.(CVE-2026-22770)

ImageMagick contains an infinite recursion vulnerability in MSL script processing that can lead to stack overflow. The vulnerability exists in the ProcessMSLScript function, where attackers can craft malicious MSL scripts to trigger infinite recursion, ultimately causing stack overflow.(CVE-2026-23874)

ImageMagick is a widely used free and open-source software for image editing and manipulation. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability exists in the XBM image decoder (ReadXBMImage function). An attacker can exploit this by crafting a malicious XBM image file, causing controlled data to be written past the bounds of an allocated heap buffer during processing. Any operation that reads or identifies an image, such as common image upload and processing pipelines, can trigger this overflow, potentially leading to arbitrary code execution or application crash.(CVE-2026-23876)

ImageMagick is free and open-source software used for editing and manipulating digital images. Versions 14.10.1 and below have a NULL pointer dereference vulnerability in the MSL (Magick Scripting Language) parser when processing <comment> tags before images are loaded. This can lead to DoS attack due to assertion failure (debug builds) or NULL pointer dereference (release builds). This issue is fixed in version 14.10.2.(CVE-2026-23952)

Use ImageMagick to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.

Security Fix(es):

A vulnerability exists in ImageMagick's BilateralBlur functionality where an invalid pointer is released when memory allocation fails, potentially leading to application crashes or security risks.(CVE-2026-22770)

ImageMagick contains an infinite recursion vulnerability in MSL script processing that can lead to stack overflow. The vulnerability exists in the ProcessMSLScript function, where attackers can craft malicious MSL scripts to trigger infinite recursion, ultimately causing stack overflow.(CVE-2026-23874)

ImageMagick is a widely used free and open-source software for image editing and manipulation. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability exists in the XBM image decoder (ReadXBMImage function). An attacker can exploit this by crafting a malicious XBM image file, causing controlled data to be written past the bounds of an allocated heap buffer during processing. Any operation that reads or identifies an image, such as common image upload and processing pipelines, can trigger this overflow, potentially leading to arbitrary code execution or application crash.(CVE-2026-23876)

ImageMagick is free and open-source software used for editing and manipulating digital images. Versions 14.10.1 and below have a NULL pointer dereference vulnerability in the MSL (Magick Scripting Language) parser when processing <comment> tags before images are loaded. This can lead to DoS attack due to assertion failure (debug builds) or NULL pointer dereference (release builds). This issue is fixed in version 14.10.2.(CVE-2026-23952)

Use ImageMagick to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.

Security Fix(es):

A vulnerability exists in ImageMagick's BilateralBlur functionality where an invalid pointer is released when memory allocation fails, potentially leading to application crashes or security risks.(CVE-2026-22770)

ImageMagick contains an infinite recursion vulnerability in MSL script processing that can lead to stack overflow. The vulnerability exists in the ProcessMSLScript function, where attackers can craft malicious MSL scripts to trigger infinite recursion, ultimately causing stack overflow.(CVE-2026-23874)

ImageMagick is a widely used free and open-source software for image editing and manipulation. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability exists in the XBM image decoder (ReadXBMImage function). An attacker can exploit this by crafting a malicious XBM image file, causing controlled data to be written past the bounds of an allocated heap buffer during processing. Any operation that reads or identifies an image, such as common image upload and processing pipelines, can trigger this overflow, potentially leading to arbitrary code execution or application crash.(CVE-2026-23876)

ImageMagick is free and open-source software used for editing and manipulating digital images. Versions 14.10.1 and below have a NULL pointer dereference vulnerability in the MSL (Magick Scripting Language) parser when processing <comment> tags before images are loaded. This can lead to DoS attack due to assertion failure (debug builds) or NULL pointer dereference (release builds). This issue is fixed in version 14.10.2.(CVE-2026-23952)

Use ImageMagick to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.

Security Fix(es):

A vulnerability exists in ImageMagick's BilateralBlur functionality where an invalid pointer is released when memory allocation fails, potentially leading to application crashes or security risks.(CVE-2026-22770)

ImageMagick contains an infinite recursion vulnerability in MSL script processing that can lead to stack overflow. The vulnerability exists in the ProcessMSLScript function, where attackers can craft malicious MSL scripts to trigger infinite recursion, ultimately causing stack overflow.(CVE-2026-23874)

ImageMagick is a widely used free and open-source software for image editing and manipulation. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability exists in the XBM image decoder (ReadXBMImage function). An attacker can exploit this by crafting a malicious XBM image file, causing controlled data to be written past the bounds of an allocated heap buffer during processing. Any operation that reads or identifies an image, such as common image upload and processing pipelines, can trigger this overflow, potentially leading to arbitrary code execution or application crash.(CVE-2026-23876)

ImageMagick is free and open-source software used for editing and manipulating digital images. Versions 14.10.1 and below have a NULL pointer dereference vulnerability in the MSL (Magick Scripting Language) parser when processing <comment> tags before images are loaded. This can lead to DoS attack due to assertion failure (debug builds) or NULL pointer dereference (release builds). This issue is fixed in version 14.10.2.(CVE-2026-23952)

Use ImageMagick to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.

Security Fix(es):

A vulnerability exists in ImageMagick's BilateralBlur functionality where an invalid pointer is released when memory allocation fails, potentially leading to application crashes or security risks.(CVE-2026-22770)

ImageMagick contains an infinite recursion vulnerability in MSL script processing that can lead to stack overflow. The vulnerability exists in the ProcessMSLScript function, where attackers can craft malicious MSL scripts to trigger infinite recursion, ultimately causing stack overflow.(CVE-2026-23874)

ImageMagick is a widely used free and open-source software for image editing and manipulation. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability exists in the XBM image decoder (ReadXBMImage function). An attacker can exploit this by crafting a malicious XBM image file, causing controlled data to be written past the bounds of an allocated heap buffer during processing. Any operation that reads or identifies an image, such as common image upload and processing pipelines, can trigger this overflow, potentially leading to arbitrary code execution or application crash.(CVE-2026-23876)

ImageMagick is free and open-source software used for editing and manipulating digital images. Versions 14.10.1 and below have a NULL pointer dereference vulnerability in the MSL (Magick Scripting Language) parser when processing <comment> tags before images are loaded. This can lead to DoS attack due to assertion failure (debug builds) or NULL pointer dereference (release builds). This issue is fixed in version 14.10.2.(CVE-2026-23952)

ImageMagick is free and open-source software used for editing and manipulating digital images. Versions prior to 7.1.2-13 have a stack overflow via infinite recursion in MSL (Magick Scripting Language) <write> command when writing to MSL format. Version 7.1.2-13 fixes the issue.

These are all security issues fixed in the ImageMagick-7.1.2.13-2.1 package on the GA media of openSUSE Tumbleweed.

This update for ImageMagick fixes the following issues:

• CVE-2026-22770: improper pointer initialization can cause denial of service (bsc#1256969).
• CVE-2026-23874: manipulation of digital images can lead to stack overflow (bsc#1256976).
• CVE-2026-23876: ImageMagick: maliciously crafted image can lead to heap buffer overflow (bsc#1256962).
• CVE-2026-23952: processing comment tag can cause null pointer dereference (bsc#1257076).
• CVE-2026-24481: Possible Heap Information Disclosure in PSD ZIP Decompression (bsc#1258743).
• CVE-2026-24484: denial of service vulnerability via multi-layer nested MVG to SVG conversion (bsc#1258790).
• CVE-2026-24485: denial of service via malformed PCD file processing (bsc#1258791).
• CVE-2026-25576: Out of bounds read in multiple coders that read raw pixel data (bsc#1258748).
• CVE-2026-25637: Denial of Service via crafted image due to memory leak (bsc#1258759).
• CVE-2026-25638: Denial of Service due to memory leak in image processing (bsc#1258793).
• CVE-2026-25794: Heap-buffer-overflow via signed integer overflow in WriteUHDRImage when writing UHDR images with large dimensions (bsc#1258749).
• CVE-2026-25795: Denial of Service due to NULL pointer dereference during temporary file creation failure (bsc#1258792).
• CVE-2026-25796: Memory leak of watermark Image object in ReadSTEGANOImage on multiple error/early-return paths (bsc#1258757).
• CVE-2026-25797: Code injection in various encoders (bsc#1258770).
• CVE-2026-25798: NULL Pointer Dereference in ClonePixelCacheRepository via crafted image (bsc#1258787).
• CVE-2026-25799: Division-by-Zero in YUV sampling factor validation leads to crash (bsc#1258786).
• CVE-2026-25897: Out-of-bounds heap write via integer overflow in sun decoder (bsc#1258799).
• CVE-2026-25898: Information disclosure or denial of service via crafted image with invalid pixel index (bsc#1258807).
• CVE-2026-25965: Policy bypass through path traversal allows reading restricted content despite secured policy (bsc#1258785).
• CVE-2026-25966: Security Policy Bypass through config/policy-secure.xml via "fd handler" leads to stdin/stdout access (bsc#1258780).
• CVE-2026-25967: Stack buffer overflow in FTXT reader via oversized integer field (bsc#1258779).
• CVE-2026-25968: MSL attribute stack buffer overflow leads to out of bounds write (bsc#1258776).
• CVE-2026-25969: Memory Leak in coders/ashlar.c (bsc#1258775).
• CVE-2026-25970: Memory corruption and denial of service via signed integer overflow in SIXEL decoder (bsc#1258802).
• CVE-2026-25971: MSL: Stack overflow in ProcessMSLScript (bsc#1258774).
• CVE-2026-25982: Heap Out-of-Bounds Read in DCM Decoder (bsc#1258772).
• CVE-2026-25983: Denial of service via crafted MSL script (bsc#1258805).
• CVE-2026-25985: Memory allocation with excessive without limits in the internal SVG decoder (bsc#1258812).
• CVE-2026-25986: Denial of Service via malicious YUV image processing (bsc#1258818).
• CVE-2026-25987: Memory disclosure and denial of service via crafted MAP files (bsc#1258821).
• CVE-2026-25988: Denial of Service due to memory leak in image processing (bsc#1258810).
• CVE-2026-25989: Integer overflow or wraparound and incorrect conversion between numeric types in the internal SVG decoder (bsc#1258771).
• CVE-2026-26066: Infinite loop when writing IPTCTEXT leads to denial of service via crafted profile (bsc#1258769).
• CVE-2026-26283: Possible infinite loop in JPEG encoder when using jpeg: extent (bsc#1258767).
• CVE-2026-26284: Heap overflow in pcd decoder leads to out of bounds read (bsc#1258765).
• CVE-2026-26983: Invalid MSL <map> can result in a use after free (bsc#1258763).
• CVE-2026-27798: Heap Buffer Over-read in WaveletDenoise when processing small images (bsc#1259018).
• CVE-2026-27799: ImageMagick has a heap Buffer Over-read in its DJVU image format handler (bsc#1259017).

Root has patched CVE-2026-23874 in the rootio-imagemagick package for Root:Debian:12. Multiple fixed versions available.

This update for ImageMagick fixes the following issues:

• CVE-2026-23874: manipulation of digital images can lead to stack overflow (bsc#1256976).
• CVE-2026-23876: maliciously crafted image can lead to heap buffer overflow (bsc#1256962).
• CVE-2026-23952: processing comment tag can cause null pointer dereference (bsc#1257076).

This update for ImageMagick fixes the following issues:

• CVE-2026-22770: improper pointer initialization can cause denial of service (bsc#1256969).
• CVE-2026-23874: manipulation of digital images can lead to stack overflow (bsc#1256976).
• CVE-2026-23876: maliciously crafted image can lead to heap buffer overflow (bsc#1256962).
• CVE-2026-23952: processing comment tag can cause null pointer dereference (bsc#1257076).

This update for ImageMagick fixes the following issues:

• CVE-2026-22770: improper pointer initialization can cause denial of service (bsc#1256969).
• CVE-2026-23874: manipulation of digital images can lead to stack overflow (bsc#1256976).
• CVE-2026-23876: maliciously crafted image can lead to heap buffer overflow (bsc#1256962).
• CVE-2026-23952: processing comment tag can cause null pointer dereference (bsc#1257076).

This update for ImageMagick fixes the following issues:

• CVE-2026-23874: manipulation of digital images can lead to stack overflow (bsc#1256976).
• CVE-2026-23876: maliciously crafted image can lead to heap buffer overflow (bsc#1256962).
• CVE-2026-23952: processing comment tag can cause null pointer dereference (bsc#1257076).