Junglewise Threat Intelligence

CVE-2026-15520: GNU LibreDWG heap overflow in decompress_R2004_section

CVE-2026-15520 · Severity: medium · CVSS 5.3 · Published 2026-07-13

Technologies: Gnu LibreDWG. Vendors: Gnu.

Executive brief

GNU LibreDWG is a library used to read and write DWG files, which are the native format for AutoCAD software. A vulnerability in the way the library handles compressed data in older DWG files could allow an attacker to cause a system crash or potentially execute unauthorized code. This occurs when the software processes a specially crafted DWG file, impacting the reliability of applications that rely on this library for CAD data conversion.

Technical details

A heap-based buffer overflow exists in GNU LibreDWG version 0.13.4-154-g0b573035 within the decompress_R2004_section function in src/decode.c. The root cause is an incorrect assignment in read_2004_compressed_section where the dec.size variable is overwritten with a smaller per-section value, causing bit_chain_alloc to shrink the buffer while the logical stream tracking continues to use the original larger size. An attacker with local access can provide a crafted DWG file to trigger an out-of-bounds write. This issue has been addressed in version 0.14.8396 by ensuring dec.size remains pinned to the true allocation size.

Affected products

  • GNU LibreDWG 0.13.4-154-g0b573035

Timeline

  • 2026-04-29: disclosed: Issue reported on GitHub
  • 2026-07-01: patched: Fix committed and version 0.14.8396 released
  • 2026-07-13: advisory: CVE published

References

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