{"id":"CVE-2026-54610","kind":"vulnerability","aliases":["CVE-2026-54610"],"related":[],"title":"LibreDWG: DWG text conversion can write to immutable input, crashing apps","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.","summary":"LibreDWG, a C library for reading and writing DWG drawing files, has a flaw in its text conversion function that writes into the caller's input buffer even though it is declared const. If that buffer is read-only, such as a string literal, the write can crash the application (denial of service), and mutable input can be silently modified.","severity":"low","cvss":3.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["c","cad","dwg","libredwg","package"],"not_affected_if":["file-only-decode-export","no-untrusted-input","version-0.14-or-later"],"how_to_check":"- Check the installed LibreDWG version with `dwg2SVG --version` or the version of the linked libredwg library; versions before `0.14` are affected.\n- Look for code calling `bit_TV_to_utf8()` that passes string literals or read-only memory and exposes it to untrusted input.","fix":"- LibreDWG: move to `0.14` or later.","status":"open","published_at":"2026-10-30T21:16:57+00:00","first_seen_at":"2026-10-30T21:25:53+00:00","triaged_at":"2026-10-30T21:27:00+00:00","updated_at":"2026-10-30T21:27:00+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-30T21:27:00Z","model":"claude-haiku-5-5","output":{"fix":"- LibreDWG: move to `0.14` or later.","reach":"unknown","title":"LibreDWG: DWG text conversion can write to immutable input, crashing apps","impact":"low","summary":"LibreDWG, a C library for reading and writing DWG drawing files, has a flaw in its text conversion function that writes into the caller's input buffer even though it is declared const. If that buffer is read-only, such as a string literal, the write can crash the application (denial of service), and mutable input can be silently modified.","audience":"developers","category":"package","nicknames":[],"who_cares":["libredwg","c","cad","dwg"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Process crashes via segfault; mutable input silently modified","analyst_note":"","how_to_check":"- Check the installed LibreDWG version with `dwg2SVG --version` or the version of the linked libredwg library; versions before `0.14` are affected.\n- Look for code calling `bit_TV_to_utf8()` that passes string literals or read-only memory and exposes it to untrusted input.","plain_action":"","needs_analyst":false,"not_affected_if":["version-0.14-or-later","no-untrusted-input","file-only-decode-export"],"who_is_affected":"Applications that link LibreDWG before 0.14 and expose its text conversion API to untrusted input, especially where the input may be a string literal or other read-only memory. Direct exploitation through normal DWG file decode and export paths is unconfirmed, since many text fields are heap allocated. Teams only decoding or exporting trusted drawings are less exposed.","user_interaction":"unknown","needs_special_setup":"yes","severity_if_unknown":"low"},"cost_usd":0.000729,"input_tokens":4314,"output_tokens":595,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-54610':14A,17A '0.14':98C,233C 'accept':115C 'affect':191C 'alia':136C 'alloc':222C 'api':197C 'app':11A 'applic':73B,192C 'bit':99C,138C,224C 'buffer':49B,58B,113C,130C,166C 'c':18B,25B,88C 'cad':19B 'caller':46B,110C,180C 'caller-own':179C 'caller-provid':109C 'caus':170C 'condit':203C 'const':55B,116C 'convers':4A,40B,196C 'crash':10A,71B 'cve':12A,15A 'declar':54B 'decode/export':212C 'denial':74B,175C 'despit':114C 'direct':204C 'draw':32B 'dwg':2A,20B,31B,94C,211C 'e2big':124C 'error':121C 'escap':148C 'even':50B 'expand':140C,142C 'exploit':208C 'expos':194C 'fault':173C 'file':33B,95C,206C 'file-trigg':205C 'fix':230C 'flaw':36B 'free':87C,127C 'function':41B,126C 'heap':221C 'iconv':120C 'immut':8A,165C 'input':9A,48B,79B,117C,135C,154C,182C,200C 'issu':228C 'librari':26B,89C 'libredwg':1A,21B,23B,84C 'liter':67B,158C 'mani':217C 'map':162C 'modifi':83B,186C 'multibyt':147C 'mutabl':78B,178C 'normal':210C 'origin':134C 'output':129C 'own':181C 'packag':22B 'pass':132C 'path':213C 'place':151C 'prior':96C 'provid':111C 'read':28B,61B,91C,160C,225C 'read-on':60B,159C 'remain':214C 'return':189C 'segment':172C 'sequenc':149C 'servic':76B,177C 'shrink':144C 'silent':82B 'src':112C 'src/bits.c':104C 'string':66B,157C,219C 'text':3A,39B 'though':51B 'trigger':207C 'tv':100C,218C,226C 'u':139C 'unconfirm':215C 'unexpect':185C 'unicod':145C 'untrust':199C 'utf8':102C 'version':232C 'write':6A,30B,43B,69B,93C,106C,168C","nicknames":[],"mitigations":[],"who_affected":"Applications that link LibreDWG before 0.14 and expose its text conversion API to untrusted input, especially where the input may be a string literal or other read-only memory. Direct exploitation through normal DWG file decode and export paths is unconfirmed, since many text fields are heap allocated. Teams only decoding or exporting trusted drawings are less exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"first_public_at":"2026-10-30T21:16:57+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-54610","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54610","severity":null,"published_at":"2026-10-30T21:16:57+00:00","modified_at":"2026-10-30T21:16:57+00:00","first_seen_at":"2026-10-30T21:25:53+00:00","fetched_at":"2026-10-30T21:25:53+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}