# CVE-2026-9502: GNU LibreDWG heap overflow in decompress_R2004_section

Source: https://junglewise.ai/threats/cve-2026-9502-gnu-libredwg-heap-overflow-in-decompress-r2004-section  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-25. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-9502 · Severity: medium · CVSS 5.3 · Published 2026-05-25

A vulnerability was found in GNU LibreDWG, a library used for reading and writing AutoCAD DWG files. An attacker could use a specially crafted file to cause a memory overflow, potentially leading to a program crash or unauthorized code execution. This issue primarily affects the 'dwgread' utility when processing certain types of compressed drawing data.

Technologies: [Gnu LibreDWG](https://junglewise.ai/threats/technologies/libredwg). Vendors: [Gnu](https://junglewise.ai/threats/vendors/gnu).

## Quick answers

**Is CVE-2026-9502 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9502 being exploited in the wild.

**How severe is CVE-2026-9502?** Medium severity, with a CVSS score of 5.3, published 25 May 2026.

**Which products and versions are affected?** Gnu LibreDWG up to 0.14.

**Is there a fix for CVE-2026-9502?** A patch was published on 2026-05-25: Patch commit e501cb9 identified Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-9502 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-9502?** Check whether you run Gnu LibreDWG at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A heap-based buffer overflow exists in GNU LibreDWG versions up to 0.14 within the decompress_R2004_section function in src/decode.c. The vulnerability is triggered during the processing of malformed DWG R2004 files using the dwgread utility. An attacker can achieve an out-of-bounds heap write by providing a crafted input file that bypasses insufficient bounds checking during decompression. This can lead to a denial of service (crash) or potentially arbitrary code execution. A patch has been released (commit e501cb9) which adds necessary validation for decompression bytes and offsets.

## Affected products

- GNU LibreDWG up to 0.14

## Timeline

- 2026-04-22: disclosed: Issue reported on GitHub by HackC0der
- 2026-05-25: advisory: CVE-2026-9502 published
- 2026-05-25: patched: Patch commit e501cb9 identified

## References

- [https://github.com/HackC0der/CVE-Repos/blob/main/libredwg/libredwg_6d6a339_heap_overflow_decompress_R2004_section.dwg](https://github.com/HackC0der/CVE-Repos/blob/main/libredwg/libredwg_6d6a339_heap_overflow_decompress_R2004_section.dwg)
- [https://github.com/LibreDWG/libredwg/commit/e501cb9926c1e9a07a0d1cc997f3e69e9be801c9](https://github.com/LibreDWG/libredwg/commit/e501cb9926c1e9a07a0d1cc997f3e69e9be801c9)
- [https://github.com/LibreDWG/libredwg/issues/1243](https://github.com/LibreDWG/libredwg/issues/1243)
- [https://vuldb.com/submit/814259](https://vuldb.com/submit/814259)
- [https://vuldb.com/vuln/365484](https://vuldb.com/vuln/365484)
- [https://vuldb.com/vuln/365484/cti](https://vuldb.com/vuln/365484/cti)
- [https://www.gnu.org/](https://www.gnu.org/)

## Related threats

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- [GNU libredwg null pointer dereference in LAYER encoding](https://junglewise.ai/threats/cve-2026-90622-gnu-libredwg-null-pointer-dereference-in-layer-encoding)
- [GNU LibreDWG heap overflow in decompress_R2004_section](https://junglewise.ai/threats/cve-2026-15520-gnu-libredwg-heap-overflow-in-decompress-r2004-section)
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