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Fencer Vulns
low 3.3

CVE-2026-54610 json

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

published 2026-10-30 9 d ago modified 2026-11-05 4 d ago also EUVD-2026-114464

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

CISA SSVC

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

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

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 Vulns 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.