# CVE-2026-54610: LibreDWG: const-input mutation and crash in bit_TV_to_utf8 error handling

Status: published. Published: 2026-10-30. Updated: 2026-11-05.

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

- fix: LibreDWG (c/c++): GitHub reports patched versions 0.14. Check the advisory for the affected release branch. (source: GitHub GHSA-5p98-8245-6hxq) — https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq

## Affected products and versions

- LibreDWG / libredwg: < 0.14 (affected). Source: CNA: GitHub_M
-  / LibreDWG (LibreDWG): <= 0.13.4.8236， (affected, GitHub advisory range). Source: GitHub GHSA-5p98-8245-6hxq

## Severity and prioritization

- CVSS 3.1: 3.3 (low); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L; source: CNA: GitHub_M

- CVSS 3.1: 3.3 (low); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.12% as of 2026-11-04; percentile 1.73%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-471, CWE-703

## Exploit evidence

- exploit: https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq (ADP: CISA-ADP)

## References

- https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/LibreDWG/libredwg/commit/08c034a224a4e9512b1cd62e74b5cf081a4cfa89 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/LibreDWG/libredwg/releases/tag/0.14 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/user-attachments/files/28631091/libredwg-bit-tv-to-utf8-submission.tar.gz (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq (ADP: CISA-ADP; exploit)

- https://github.com/LibreDWG/libredwg/commit/08c034a224a4e9512b1cd62e74b5cf081a4cfa89 (security-advisories@github.com)

- https://github.com/LibreDWG/libredwg/releases/tag/0.14 (security-advisories@github.com)

- https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq (security-advisories@github.com)

- https://github.com/user-attachments/files/28631091/libredwg-bit-tv-to-utf8-submission.tar.gz (security-advisories@github.com)

- https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq (GitHub Security Advisories; advisory)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-54610; retrieved 2026-11-05; source updated 2026-11-05

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54610; retrieved 2026-11-03; source updated 2026-11-02

- GitHub Security Advisories: https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq; retrieved 2026-11-05; source updated 2026-06-27

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-54610; retrieved 2026-11-05; source updated Not reported

Revision: 4f3ff448488895b31737417b81b3219c6099daf3ca501ed1f6b61af75263554e

Canonical: https://y2.dev/cve/CVE-2026-54610

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