{"id":"CVE-2026-88077","kind":"vulnerability","aliases":["CVE-2026-88077"],"related":[],"title":"Microsoft Edge: integer overflow lets a network attacker gain elevated privileges","description":"Integer overflow or wraparound in Microsoft Edge (Chromium-based) allows an unauthorized attacker to elevate privileges over a network.","summary":"Integer overflow (CWE-190) in Microsoft Edge (Chromium-based). An attacker who gets a user to open a crafted website could gain SYSTEM privileges. Microsoft rates it Important, CVSS 8.8, not exploited, not publicly disclosed. Fixed in 154.0.4258.62.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Microsoft Edge (Chromium-based)","fixed":["154.0.4258.62"],"affected":"< 154.0.4258.62","ecosystem":"vendor"}],"ecosystems":[],"tags":["chromium","microsoft-edge","other","windows"],"not_affected_if":[],"how_to_check":"Open edge://settings/help (Help and feedback > About Microsoft Edge). Versions below 154.0.4258.62 are vulnerable.","fix":"Update Microsoft Edge (Chromium-based) to 154.0.4258.62 or later (Edge menu > Help and feedback > About Microsoft Edge).","status":"open","published_at":"2026-10-29T16:19:52+00:00","first_seen_at":"2026-10-29T16:26:01+00:00","triaged_at":"2026-10-29T16:27:56+00:00","updated_at":"2026-10-29T16:34:56+00:00","category":"other","confidence":0.85,"triage":{"at":"2026-10-29T16:27:56Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Edge: integer overflow lets a network attacker gain elevated privileges","impact":"high","summary":"An integer overflow in Microsoft Edge (Chromium-based) can be abused by an unauthorized attacker over a network to elevate privileges. The sources give a CVSS score of 8.8 but do not say what the attacker can then do.","audience":"everyone","category":"other","nicknames":[],"who_cares":["microsoft-edge","windows","chromium"],"confidence":0.5,"fix_status":"unknown","needs_auth":"unknown","worst_case":"Attacker gains elevated privileges on the affected machine over the network.","analyst_note":"Check the NVD entry and Microsoft's security update guide for the fixed Edge version, required setup, and whether user interaction is needed.","how_to_check":"- Check the installed Edge version (Edge menu > Help and feedback > About Microsoft Edge) against the fixed version, which the sources do not state.","plain_action":"Update Microsoft Edge to the latest version: Settings > About Microsoft Edge.","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Any machine running a Chromium-based Microsoft Edge build that is not yet updated is potentially exposed. The sources do not describe the required configuration, user interaction, or the exact attack path.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000666,"input_tokens":4081,"output_tokens":515,"severity_before":"high"},"analyst_status":"done","analyst_note":"Check the NVD entry and Microsoft's security update guide for the fixed Edge version, required setup, and whether user interaction is needed.","search":"'-190':32B '-2026':13A,16A '-88077':14A,17A '154.0.4258.62':67B '8.8':59B 'allow':78C 'attack':8A,40B,81C 'base':38B,77C 'based':22A 'chromium':21A,23B,37B,76C 'chromium-bas':36B,75C 'chromium-based':20A 'could':50B 'craft':48B 'cve':12A,15A 'cvss':58B 'cwe':31B 'disclos':64B 'edg':2A,26B,35B,74C 'edge':19A 'elev':10A,83C 'exploit':61B 'fix':65B 'gain':9A,51B 'get':42B 'import':57B 'integ':3A,29B,68C 'let':5A 'microsoft':1A,18A,25B,34B,54B,73C 'microsoft-edg':24B 'network':7A,87C 'open':46B 'overflow':4A,30B,69C 'privileg':11A,53B,84C 'public':63B 'rate':55B 'system':52B 'unauthor':80C 'user':44B 'websit':49B 'window':28B 'wraparound':71C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Microsoft Edge (Chromium-based) older than 154.0.4258.62. Exploitation needs the user to view an attacker-controlled page, usually through a phishing link. Machines with Edge already updated can skip it.","tier":"B","verified":{"fix":{"at":"2026-10-29T16:34:56Z","by":"analyst","doc":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88077","run_id":1065},"products":{"at":"2026-10-29T16:34:56Z","by":"analyst","doc":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88077","run_id":1065},"how_to_check":{"at":"2026-10-29T16:34:56Z","by":"analyst","doc":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88077","run_id":1065},"who_affected":{"at":"2026-10-29T16:34:56Z","by":"analyst","doc":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88077","run_id":1065}},"analyst_revisit_at":null,"fix_status":"available","audience":"everyone","plain_action":"Update Microsoft Edge to the latest version: Settings > About Microsoft Edge.","first_public_at":"2026-10-29T16:19:52+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-88077","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88077","severity":null,"published_at":"2026-10-29T16:19:52+00:00","modified_at":"2026-10-29T16:19:53+00:00","first_seen_at":"2026-10-29T16:26:01+00:00","fetched_at":"2026-10-29T16:26:01+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-88077:1065","url":null,"severity":null,"published_at":"2026-10-29T16:34:56+00:00","modified_at":"2026-10-29T16:34:56+00:00","first_seen_at":"2026-10-29T16:34:56+00:00","fetched_at":"2026-10-29T16:34:56+00:00","note":"Read MSRC page: fixed in Edge 154.0.4258.62 (Oct 26 2026), not exploited, not public, Less Likely; user must visit crafted site; SYSTEM privileges per FAQ. No PoC checked beyond MSRC."}],"documents":[{"id":17782,"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88077","title":"MSRC: CVE-2026-88077 Edge (Chromium-based) Elevation of Privilege","kind":"advisory","source":"analyst","publisher":null,"text":"Released Oct 26, 2026. CWE-190. CVSS 8.8 (temporal 7.7), AV:N/AC:L/PR:N/UI:R. Not publicly disclosed, not exploited, Exploitation Less Likely. Attacker could gain SYSTEM privileges via crafted website the user is convinced to view. Fixed build 154.0.4258.62 (Oct 26, 2026). Credit: Nan Wang (@eternalsakura13) and Ziling Chen.","published_at":null,"relation":"advisory","confidence":null,"note":null}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}