{"id":"CVE-2026-126546","kind":"vulnerability","aliases":["CVE-2026-126546"],"related":[],"title":"Viber for iOS: crafted GIF with zero dimensions crashes the app","description":"Viber for iOS through 29.4.0.24 fails to validate the logical screen width and height in received GIF headers, allowing attackers to crash the app. Attackers can send a crafted GIF with zero dimensions that triggers an uncaught NSInternalInconsistencyException, aborting the app with SIGABRT when opened.","summary":"Viber for iOS through 29.4.0.24 does not validate the logical screen width and height in GIF headers. A crafted GIF with zero dimensions triggers an uncaught exception that aborts the app when the image is opened, so an attacker can crash it.","severity":"medium","cvss":5.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ios","other","viber"],"not_affected_if":["android","newer-version"],"how_to_check":"- Open Viber, go to Settings > About and compare the version with `29.4.0.24`, which is the last affected version according to the description.","fix":null,"status":"open","published_at":"2026-11-11T01:17:16+00:00","first_seen_at":"2026-11-11T01:24:34+00:00","triaged_at":"2026-11-11T01:25:53+00:00","updated_at":"2026-11-11T01:25:53+00:00","category":"other","confidence":0.6,"triage":{"at":"2026-11-11T01:25:53Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"internet","title":"Viber for iOS: crafted GIF with zero dimensions crashes the app","impact":"low","summary":"Viber for iOS through 29.4.0.24 does not validate the logical screen width and height in GIF headers. A crafted GIF with zero dimensions triggers an uncaught exception that aborts the app when the image is opened, so an attacker can crash it.","audience":"everyone","category":"other","nicknames":[],"who_cares":["viber","ios"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"App crashes when a crafted GIF is opened","analyst_note":"","how_to_check":"- Open Viber, go to Settings > About and compare the version with `29.4.0.24`, which is the last affected version according to the description.","plain_action":"Update Viber on your iPhone to a version later than 29.4.0.24 from the App Store, if an update is available.","product_name":"","needs_analyst":false,"not_affected_if":["android","newer-version"],"who_is_affected":"Users of Viber for iOS through 29.4.0.24 who receive images from other people. The flaw is a crash rather than code execution, and the sources do not say whether any fixed version exists.","user_interaction":"yes","product_ecosystem":"","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000688,"input_tokens":4584,"output_tokens":460,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-126546':14A,17A '-2026':13A,16A '29.4.0.24':25B,66C 'abort':49B,100C 'allow':80C 'app':11A,51B,85C,102C 'attack':59B,81C,86C 'craft':4A,39B,90C 'crash':9A,61B,83C 'cve':12A,15A 'dimens':8A,43B,94C 'except':47B 'fail':67C 'gif':5A,36B,40B,78C,91C 'header':37B,79C 'height':34B,75C 'imag':54B 'io':3A,18B,23B,64C 'logic':30B,71C 'nsinternalinconsistencyexcept':99C 'open':56B,106C 'receiv':77C 'screen':31B,72C 'send':88C 'sigabrt':104C 'trigger':44B,96C 'uncaught':46B,98C 'valid':28B,69C 'viber':1A,20B,21B,62C 'width':32B,73C 'zero':7A,42B,93C","nicknames":[],"mitigations":[],"who_affected":"Users of Viber for iOS through 29.4.0.24 who receive images from other people. The flaw is a crash rather than code execution, and the sources do not say whether any fixed version exists.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":"Update Viber on your iPhone to a version later than 29.4.0.24 from the App Store, if an update is available.","pkeys":[],"ptokens":[],"labels":["ios","medium","other","viber"],"campaign_type":null,"search_a":"'-126546':14A,17A '-2026':13A,16A 'app':11A 'craft':4A 'crash':9A 'cve':12A,15A 'dimens':8A 'gif':5A 'io':3A 'viber':1A 'zero':7A","search_b":"'29.4.0.24':25B 'abort':49B 'app':51B 'attack':59B 'craft':39B 'crash':61B 'dimens':43B 'except':47B 'gif':36B,40B 'header':37B 'height':34B 'imag':54B 'io':18B,23B 'logic':30B 'open':56B 'screen':31B 'trigger':44B 'uncaught':46B 'valid':28B 'viber':20B,21B 'width':32B 'zero':42B","search_c":"'29.4.0.24':66C 'abort':100C 'allow':80C 'app':85C,102C 'attack':81C,86C 'craft':90C 'crash':83C 'dimens':94C 'fail':67C 'gif':78C,91C 'header':79C 'height':75C 'io':64C 'logic':71C 'nsinternalinconsistencyexcept':99C 'open':106C 'receiv':77C 'screen':72C 'send':88C 'sigabrt':104C 'trigger':96C 'uncaught':98C 'valid':69C 'viber':62C 'width':73C 'zero':93C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-11T01:17:16+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/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":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-126546","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126546","severity":null,"published_at":"2026-11-11T01:17:16+00:00","modified_at":"2026-11-11T01:17:16+00:00","first_seen_at":"2026-11-11T01:24:34+00:00","fetched_at":"2026-11-11T01:24:34+00:00","note":null}],"documents":[{"id":121306,"url":"https://www.vulncheck.com/advisories/viber-for-ios-through-29.4.0.24-denial-of-service-via-malformed-gif","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}