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Fencer Intel
low 3.3

CVE-2026-54610 json

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

published 4mo ago modified 7d ago also EUVD-2026-114464 , GHSA-5p98-8245-6hxq

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository LibreDWG/libredwg. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
3.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits
0
none known

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 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.

Patch / fix

  • gnu libredwg 0.14

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7d ago

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/LibreDWG/libredwg/security/advisories/GHSA-5p98-8245-6hxq referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 3.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

Affected products

  • LibreDWG libredwg

Classification

Weakness
  • CWE-471 Modification of Assumed-Immutable Data (MAID)
  • CWE-703 Improper Check or Handling of Exceptional Conditions

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of LibreDWG/libredwg published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.