{"basis":"claimed","id":"CVE-2026-121615","name":"Linksys E5600 Login mesh_login.cgi improper authentication","vendorProject":"Linksys","product":"E5600","publishedAt":"2026-11-04","cvss":{"score":10,"severity":"CRITICAL","version":"4.0"},"exploited":null,"epss":null,"coverage":{"cloudflare":{"status":"none","firstOn":null,"daysToRule":null},"aws":{"status":"none","firstOn":null,"daysToRule":null},"azure":{"status":"none","firstOn":null,"daysToRule":null},"google":{"status":"none","firstOn":null,"daysToRule":null},"fastly":{"status":"none","firstOn":null,"daysToRule":null},"vercel":{"status":"none","firstOn":null,"daysToRule":null},"f5":{"status":"none","firstOn":null,"daysToRule":null},"akamai":{"status":"no_source","firstOn":null,"daysToRule":null},"crs":{"status":"none","firstOn":null,"daysToRule":null}},"title":"Linksys E5600 Login mesh_login.cgi improper authentication","description":"A vulnerability was determined in Linksys E5600 1.1.0.26. Affected is an unknown function of the file /cgi-bin/mesh_login.cgi of the component Login Handler. Executing a manipulation can lead to improper authentication. The attack can be launched remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way. This vulnerability only affects products that are no longer supported by the maintainer.","cwes":["CWE-287"],"vendors":[{"vendor":"cloudflare","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"aws","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"azure","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"google","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"fastly","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"vercel","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"f5","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"akamai","status":"no_source","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"crs","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]}],"updatedAt":"2026-11-04T02:40:08.347Z","cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P","ssvc":null,"kevAction":null,"kevNotes":null,"references":[{"url":"https://vuldb.com/vuln/430463","name":"VDB-430463 | Linksys E5600 Login mesh_login.cgi improper authentication","tags":["vdb-entry"]},{"url":"https://vuldb.com/vuln/430463/cti","name":"VDB-430463 | CTI Indicators (IOB, IOC, IOA)","tags":["signature","permissions-required"]},{"url":"https://vuldb.com/cve/CVE-2026-121615","name":"CVE-2026-121615 | CVE Analysis and Report","tags":["third-party-advisory"]},{"url":"https://vuldb.com/submit/1023310","name":"Submit #1023310 | Linksys E5600 1.1.0.26 Improper Authentication (CWE-287)","tags":["third-party-advisory"]},{"url":"https://github.com/Zimo-666/E5600-cves/tree/main/02-mesh-login-auth-bypass","name":null,"tags":["exploit"]},{"url":"https://www.linksys.com/","name":null,"tags":["product"]}],"affected":[{"vendor":"Linksys","product":"E5600","affected":["1.1.0.26"],"fixed":[]}],"briefing":{"status":{"id":"monitor","label":"Monitor"},"why":"It is reachable over the network without credentials or any user interaction (CVSS 10.0). No edge WAF vendor names it in a changelog, so default managed rules may or may not catch it. Exploitation in the wild is not established by CISA KEV.","who":"Teams running Linksys E5600 (1.1.0.26). Prioritise internet-facing instances.","what_to_do":[{"text":"Apply the vendor's fix; the advisory lists the affected and fixed versions."},{"text":"Do not rely on WAF defaults: no edge vendor names this CVE. Restrict access to the vulnerable component or add a custom rule until it is patched.","href":"#edge","linkText":"Edge coverage"},{"text":"Check which WAF sits in front of your site and whether it covers this CVE.","href":"#check","linkText":"Check your domain"}],"evidence":[{"heading":"CVE record","text":"CVSS 4.0 10.0 (critical). Weakness: CWE-287.","links":[{"label":"CVE-2026-121615","href":"https://www.cve.org/CVERecord?id=CVE-2026-121615"},{"label":"NVD","href":"https://nvd.nist.gov/vuln/detail/CVE-2026-121615"}]},{"heading":"Exploit evidence","text":"No public exploit code found in Exploit-DB, Metasploit, nuclei-templates or GitHub. That does not mean none exists.","links":[]},{"heading":"CISA KEV","text":"Not in the KEV catalog (catalog 2026.11.03, checked 2026-11-04). Absence from KEV is not evidence that it cannot be exploited.","links":[{"label":"CISA KEV catalog","href":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog"}]},{"heading":"WAF vendor statements","text":"No edge vendor changelog names it.","links":[]}],"agent_prompt":"Assess whether the infrastructure available to you is affected by CVE-2026-121615 (Linksys E5600 Login mesh_login.cgi improper authentication). Perform a read-only assessment within your authorized access. Do not send exploit traffic, scan third-party systems, change configuration or restart services.\n\n1. Verify the CVE record at https://www.cve.org/CVERecord?id=CVE-2026-121615 and the vendor advisory. Establish affected and fixed versions, including vendor backports. The record lists: Linksys E5600: affected 1.1.0.26. Cite sources and retrieval dates; flag anything you cannot verify.\n2. Inventory deployments of Linksys E5600: asset, environment, owner where known, installed version or build, and how you confirmed it (package metadata, a version endpoint, image tags). An image tag alone does not prove the running version.\n3. Identify which deployments are reachable from the internet or untrusted networks, and through which paths (direct origin, load balancer, CDN or WAF).\n4. Assess compensating controls separately from patch status. Current edge WAF coverage for this CVE: no edge WAF vendor names it. Live data: https://cve.vigilbase.com/api/v1/cves/CVE-2026-121615. Check whether the rule is enabled and in block mode on each path, and whether any path bypasses the WAF. A WAF rule is not a patch.\n5. Check logs on exposed instances for requests matching the public exploit, if your access allows.\n\nReturn a short summary and a table: asset | version/build | assessment (affected, fixed, not applicable, unknown) | exposure | compensating control | evidence | next action. List what you could not assess and the access needed to resolve it. Do not infer absence of compromise from patch status or a lack of alerts.\n\nRemediation guidance: Apply the vendor's fix; the advisory lists the affected and fixed versions. Do not rely on WAF defaults: no edge vendor names this CVE. Restrict access to the vulnerable component or add a custom rule until it is patched.\nMore: https://cve.vigilbase.com/cve/CVE-2026-121615"},"measured":[],"sightings":null,"social":{"total":10,"first_seen":"2026-11-04T02:37:39.000Z","daily":[{"day":"2026-10-22","posts":0},{"day":"2026-10-23","posts":0},{"day":"2026-10-24","posts":0},{"day":"2026-10-25","posts":0},{"day":"2026-10-26","posts":0},{"day":"2026-10-27","posts":0},{"day":"2026-10-28","posts":0},{"day":"2026-10-29","posts":0},{"day":"2026-10-30","posts":0},{"day":"2026-10-31","posts":0},{"day":"2026-11-01","posts":0},{"day":"2026-11-02","posts":0},{"day":"2026-11-03","posts":0},{"day":"2026-11-04","posts":10}],"top_posts":[{"source":"bluesky","kind":"post","url":"https://bsky.app/profile/thehackerwire.bsky.social/post/3mzhnqyyyee2l","author":"thehackerwire.bsky.social","author_name":"TheHackerWire","avatar_url":"https://cdn.bsky.app/img/avatar/plain/did:plc:yhhqv2c64q5xv7mdwy6dbwqq/bafkreibnofwla3zl6epzaubi52gnzfchkqufk3k3eaktsy4ibsm7dtemeu","text":"🔴 CVE-2026-121615 - Critical (10)\n\nA vulnerability was determined in Linksys E5600 1.1.0.26. Affected is an unknown function of the ...\n\nhttps://www.thehackerwire.com/vulnerability/CVE-2026-121615/\n\n#infosec #cybersecurity #CVE #vulnerability #security #patchstack","engagement":0,"posted_at":"2026-11-04T05:48:32.000Z"},{"source":"mastodon","kind":"post","url":"https://mastodon.social/@thehackerwire/117556595285818405","author":"thehackerwire","author_name":"TheHackerWire","avatar_url":"https://files.mastodon.social/accounts/avatars/115/755/483/699/003/887/original/be4cc997d460de98.jpg","text":"🔴 CVE-2026-121615 - Critical (10) A vulnerability was determined in Linksys E5600 1.1.0.26. Affected is an unknown function of the file /cgi-bin/mesh_login.cgi of the component Login Handler. Executing a manipulation can lead to improper authentication. The attack can be launch…","engagement":0,"posted_at":"2026-11-04T05:48:10.373Z"},{"source":"bluesky","kind":"post","url":"https://bsky.app/profile/stackflag.bsky.social/post/3mzhissx42322","author":"stackflag.bsky.social","author_name":"STACKFLAG","avatar_url":"https://cdn.bsky.app/img/avatar/plain/did:plc:zhe53h7ajlloep2oso5pqxzj/bafkreigtuhh5jkztpd2jbpwmsgwljrln6miskcl62es3xsgiziejo5gdve","text":"CVE-2026-121615\nThe login page on Linksys E5600 routers (firmware version 1.1.0.26) contains a flaw that lets an attacker bypass authentication from a remote location. This could let an unauthorized person gain access to the…\n\nToo many irrelevant or confusing CVEs? Use stackflag…","engagement":0,"posted_at":"2026-11-04T04:20:00.000Z"},{"source":"x","kind":"post","url":"https://x.com/EnclaveRadar/status/2117833164693356817","author":"EnclaveRadar","author_name":"Enclave Radar","avatar_url":"https://pbs.twimg.com/profile_images/2116963272138121217/F3O3nWOo_bigger.jpg","text":"🆕 New CVE: CVE-2026-121615 (CVSS 10.0)\nLinksys E5600 · Authentication bypass\nRemote, no login needed.\n\nA vulnerability was determined in Linksys E5600 1.1.0.26.\n\nhttps://t.co/2AL8rhGvUe","engagement":0,"posted_at":"2026-11-04T04:15:48.000Z"},{"source":"bluesky","kind":"post","url":"https://bsky.app/profile/stemshop.bsky.social/post/3mzhi5m6lnw2v","author":"stemshop.bsky.social","author_name":"stemshop.bsky.social","avatar_url":"https://cdn.bsky.app/img/avatar/plain/did:plc:6zpzsab44xavrl46jqvba5wb/bafkreid2zcmne7vr45ck2bkvmhnf4occned3jmavshzk2fh5j5qpbtluja","text":"🚨 CVE-2026-121615 — CVSS 9.3 CRITICAL\n\nA vulnerability was determined in Linksys E5600 1.1.0.26. Affected is an unknown function of the file /cgi-...\n\n🔎 https://stemshop.top/cve/CVE-2026-121615\n\n#CVE #CyberSecurity #InfoSec","engagement":0,"posted_at":"2026-11-04T04:08:12.000Z"},{"source":"x","kind":"post","url":"https://x.com/cvedotnew/status/2117829210924298476","author":"cvedotnew","author_name":"cve.new","avatar_url":"https://pbs.twimg.com/profile_images/2116082780773773313/yYiFc4CS_bigger.jpg","text":"CVE-2026-121615 · CRITICAL · CVSS 10.0\n\nA vulnerability in Linksys E5600 version 1.1.0.26 allows remote improper authentication via the mesh_login.cgi file. The vendor has not responded to disclosure.\n\nCVSS 2.0 · VulDB\nhttps://t.co/HrfuBd0mQX","engagement":0,"posted_at":"2026-11-04T04:00:05.000Z"},{"source":"bluesky","kind":"post","url":"https://bsky.app/profile/aiuto-ch.bsky.social/post/3mzhg4pohfbgn","author":"aiuto-ch.bsky.social","author_name":"Aiutocomputerhelp.it","avatar_url":"https://cdn.bsky.app/img/avatar/plain/did:plc:6hebbmvhq754xdlxs3wjjpdu/bafkreib45myxtpufegfcutn345gwgzpcoypnpxx3374s7dolacacfow67u","text":"CVE Radar | CVE-2026-121615 | CVSS 10.0\n\nCritical Authentication Bypass in Linksys E5600\n\nNVD describes CVE-2026-121615 in Linksys E5600 version 1.1.0.26, involving the Login Handler.\n\nFull analysis: https://t.me/aiutocomputerhelp_lab/1366","engagement":0,"posted_at":"2026-11-04T03:31:57.332Z"},{"source":"x","kind":"post","url":"https://x.com/agentprime_io/status/2117821475260375384","author":"agentprime_io","author_name":"AgentPrime","avatar_url":"https://pbs.twimg.com/profile_images/2116608039792807936/JPVfQn5N_bigger.jpg","text":"🔴 Linksys E5600: Linksys E5600 Login mesh_login.cgi improper authentication (CVE-2026-121615)\nNo fix listed yet\nhttps://t.co/fSLnkZoHHm","engagement":0,"posted_at":"2026-11-04T03:29:21.000Z"},{"source":"bluesky","kind":"post","url":"https://bsky.app/profile/patchthecve.bsky.social/post/3mzhd6qqcgc2f","author":"patchthecve.bsky.social","author_name":null,"avatar_url":"https://cdn.bsky.app/img/avatar/plain/did:plc:5mmktbw2msy3zitzvymgy3yc/bafkreiekwdtemzouzy5tk5fe744sm77vkihsdj3t44wvqrqmiqrtpb3vum","text":"CVE-2026-121615 CRITICAL (CVSS 10)\nA vulnerability was determined in Linksys E5600 1.1.0.26\nFix: https://patchthecve.com/cve/CVE-2026-121615.html","engagement":0,"posted_at":"2026-11-04T02:39:22.000Z"},{"source":"x","kind":"post","url":"https://x.com/cvedotnow/status/2117808465343123624","author":"cvedotnow","author_name":"cve.now","avatar_url":"https://pbs.twimg.com/profile_images/2114469817906577408/drWsbSgs_bigger.jpg","text":"🆕 New CVE\nLinksys E5600: remote authentication bypass in mesh_login.cgi (CVE-2026-121615)\nA remote attacker can bypass login checks and access the device without valid credentials.\nNo patch listed yet\nhttps://t.co/rXnyzkwvdz","engagement":0,"posted_at":"2026-11-04T02:37:39.000Z"}],"exploit_repositories":[]}}