CVE-2026-54610

LibreDWG: const-input mutation and crash in bit_TV_to_utf8 error handling

Published Oct 30, 2026 CVSS 3.1 · 3.3 Low EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Libredwg
Libredwg libredwg
Vendors & Products Libredwg
Libredwg libredwg
Type Values Removed Values Added
Description 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.
Title LibreDWG: const-input mutation and crash in bit_TV_to_utf8 error handling
Weaknesses CWE-471
CWE-703
References
Metrics cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 5, 2026, 2:47 AM
Reserved
Jun 15, 2026, 7:45 PM
Status
Deferred
Published
Oct 30, 2026, 9:16 PM
Modified
Nov 5, 2026, 3:17 AM