{"id":"CVE-2026-92454","kind":"vulnerability","aliases":["CVE-2026-92454"],"related":[],"title":"GUIX JPEG decoder: truncated markers read past buffer, zero sampling hangs","description":"The GUIX software JPEG decoder reads four kinds of marker segment without checking that each is long enough to hold what it reads. A truncated segment is therefore read past the end of the caller's image buffer. Separately, a zero chroma sampling factor makes the block decode loop non-terminating. Both reproduce in the default configuration, in which `GX_SOFTWARE_DECODER_SUPPORT` is enabled.","summary":"The GUIX software JPEG decoder reads four kinds of marker segment without checking their length, so a truncated segment is read past the end of the image buffer. A zero chroma sampling factor also makes the block decode loop never finish, which can hang the process.","severity":"medium","cvss":6.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["embedded","guix","image-decoding","package"],"not_affected_if":["no-untrusted-jpeg-input"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-20T15:17:36+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","triaged_at":"2026-10-25T03:44:43+00:00","updated_at":"2026-10-25T03:44:43+00:00","category":"package","confidence":0.4,"triage":{"at":"2026-10-25T03:44:43Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"unknown","title":"GUIX JPEG decoder: truncated markers read past buffer, zero sampling hangs","impact":"medium","summary":"The GUIX software JPEG decoder reads four kinds of marker segment without checking their length, so a truncated segment is read past the end of the image buffer. A zero chroma sampling factor also makes the block decode loop never finish, which can hang the process.","category":"package","nicknames":[],"who_cares":["guix","embedded","image-decoding"],"confidence":0.4,"needs_auth":"no","worst_case":"out-of-bounds memory read or a decoder hang from a crafted JPEG","analyst_note":"Find the affected GUIX versions and the fixed release in the NVD entry (https://nvd.nist.gov/vuln/detail/CVE-2026-92454) and any vendor advisory, and confirm whether the read is only a crash or leaks data.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-untrusted-jpeg-input"],"who_is_affected":"Applications built with the GUIX software JPEG decoder that decode JPEG images from untrusted sources. The sources describe the bug as reproducing in the default configuration, where `GX_SOFTWARE_DECODER_SUPPORT` is enabled, so a default build is exposed. Teams that never decode attacker-supplied JPEGs with GUIX are unlikely to be reached.","user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000604,"input_tokens":3355,"output_tokens":536,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-92454':14A,17A 'also':57B 'block':60B,116C 'buffer':8A,51B,107C 'caller':104C 'check':36B,82C 'chroma':54B,111C 'configur':127C 'cve':12A,15A 'decod':3A,22B,28B,61B,74C,117C,132C 'default':126C 'embed':18B 'enabl':135C 'end':47B,101C 'enough':87C 'factor':56B,113C 'finish':64B 'four':30B,76C 'guix':1A,19B,25B,71C 'gx':130C 'hang':11A,67B 'hold':89C 'imag':21B,50B,106C 'image-decod':20B 'jpeg':2A,27B,73C 'kind':31B,77C 'length':38B 'long':86C 'loop':62B,118C 'make':58B,114C 'marker':5A,33B,79C 'never':63B 'non':120C 'non-termin':119C 'packag':23B 'past':7A,45B,99C 'process':69B 'read':6A,29B,44B,75C,92C,98C 'reproduc':123C 'sampl':10A,55B,112C 'segment':34B,42B,80C,95C 'separ':108C 'softwar':26B,72C,131C 'support':133C 'termin':121C 'therefor':97C 'truncat':4A,41B,94C 'without':35B,81C 'zero':9A,53B,110C","nicknames":[],"mitigations":[],"who_affected":"Applications built with the GUIX software JPEG decoder that decode JPEG images from untrusted sources. The sources describe the bug as reproducing in the default configuration, where `GX_SOFTWARE_DECODER_SUPPORT` is enabled, so a default build is exposed. Teams that never decode attacker-supplied JPEGs with GUIX are unlikely to be reached.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T15:17:36+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"emo@eclipse.org","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-92454","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92454","severity":null,"published_at":"2026-10-20T15:17:36+00:00","modified_at":"2026-10-20T19:48:50+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","fetched_at":"2026-10-23T22:28:58+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"}