---
id: CVE-2026-54610
title: 'LibreDWG: const-input mutation and crash in bit_TV_to_utf8 error handling'
summary: >-
  LibreDWG is a free C library to read and write DWG files. Prior to 0.14,
  `bit_TV_to_utf8()` in `src/bits.c` can write to the caller-provided `src`
  buffer despite accepting const input. On an `iconv()` error other than
  `E2BIG`, the functi…
severity: low
cvss: 3.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-471
  - CWE-703
vendor: LibreDWG
product: libredwg
affected:
  - libredwg < 0.14
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T02:47:14.068437Z'
exploitAvailable: true
published: '2026-10-30'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T02:47:43.120Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-54610'
references:
  - url: >-
      https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq
    label: >-
      https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq
  - url: >-
      https://github.com/LibreDWG/libredwg/commit/08c034a224a4e9512b1cd62e74b5cf081a4cfa89
    label: >-
      https://github.com/LibreDWG/libredwg/commit/08c034a224a4e9512b1cd62e74b5cf081a4cfa89
  - url: 'https://github.com/LibreDWG/libredwg/releases/tag/0.14'
    label: 'https://github.com/LibreDWG/libredwg/releases/tag/0.14'
  - url: >-
      https://github.com/user-attachments/files/28631091/libredwg-bit-tv-to-utf8-submission.tar.gz
    label: >-
      https://github.com/user-attachments/files/28631091/libredwg-bit-tv-to-utf8-submission.tar.gz
tags:
  - cve.org
  - exploit-available
epss: 0.00118
epssPercentile: 0.01732
ingestedAt: '2026-11-05T21:36:00.711Z'
---

## Overview

LibreDWG is a free C library to read and write DWG files. Prior to 0.14, `bit_TV_to_utf8()` in `src/bits.c` can write to the caller-provided `src` buffer despite accepting const input. On an `iconv()` error other than `E2BIG`, the function frees its output buffer and passes the original input alias to `bit_u_expand()`, which expands or shrinks Unicode and multibyte escape sequences in place. If the input is a string literal, read-only mapping, or other immutable buffer, the write can cause a segmentation fault and denial of service; mutable caller-owned input can be unexpectedly modified before being returned. This affects applications that expose the conversion API to untrusted input under those conditions. Direct file-triggered exploitability through normal DWG decode/export paths remains unconfirmed because many TV strings are heap allocated by bit_read_TV(). This issue is fixed in version 0.14.

## Affected

- `libredwg < 0.14`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.