{"basis":"claimed","id":"CVE-2026-121803","name":"CVE-2026-121803","vendorProject":null,"product":null,"publishedAt":"2026-11-04","cvss":null,"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":null,"description":null,"cwes":[],"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":"2026-11-04T04:45:08.749Z","cvssVector":null,"ssvc":null,"kevAction":null,"kevNotes":null,"references":[],"affected":[],"briefing":{"status":{"id":"monitor","label":"Monitor"},"why":"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":null,"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":"No CVSS score in the record.","links":[{"label":"CVE-2026-121803","href":"https://www.cve.org/CVERecord?id=CVE-2026-121803"},{"label":"NVD","href":"https://nvd.nist.gov/vuln/detail/CVE-2026-121803"}]},{"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-2026-121803 (CVE-2026-121803). 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-2026-121803 and the vendor advisory. Establish affected and fixed versions, including vendor backports. Cite sources and retrieval dates; flag anything you cannot verify.\n2. Inventory deployments of CVE-2026-121803: 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-2026-121803. 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-2026-121803"},"measured":[],"sightings":null,"social":{"total":3,"first_seen":"2026-11-04T04:40:00.000Z","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":3}],"top_posts":[{"source":"bluesky","kind":"post","url":"https://bsky.app/profile/cve.skyfleet.blue/post/6eaupuia26lhd","author":"cve.skyfleet.blue","author_name":"CVE Alerts ","avatar_url":"https://cdn.bsky.app/img/avatar/plain/did:plc:myutg2pwkjbukv7pq2hp5mtl/bafkreidzrx72dabuipp2ej2gldupqzv5nbtbez7tv4n26ekzjsot6ocdam","text":"CVE-2026-121803 - Out-of-bounds Write in UFS Firmware\nCVE ID : CVE-2026-121803\n \n Published : Nov. 4, 2026, 4:17 a.m. | 47 minutes ago\n \n Description : In UFS Field Firmware Update (FFU) functionality, there is a possible out-of-bounds write due to missing bounds checking on t...","engagement":0,"posted_at":"2026-11-04T05:20:23.310Z"},{"source":"x","kind":"post","url":"https://x.com/ParameterWatch/status/2117845744510193802","author":"ParameterWatch","author_name":"Parameter Watch","avatar_url":"https://pbs.twimg.com/profile_images/2104287089877712896/fgf1DqZt_bigger.jpg","text":"🚨 CVE-2026-121803 (9.3) 🚨\n\nUnisoc's UFS firmware update code lets any app on the device run code or crash the device with a malformed update.\n\nUFS is a flash storage standard, and Field Firmware Update is how its firmware gets replaced. No fixed version is named. https://t.co/…","engagement":0,"posted_at":"2026-11-04T05:05:47.000Z"},{"source":"bluesky","kind":"post","url":"https://bsky.app/profile/stackflag.bsky.social/post/3mzhjwknkpq22","author":"stackflag.bsky.social","author_name":"STACKFLAG","avatar_url":"https://cdn.bsky.app/img/avatar/plain/did:plc:zhe53h7ajlloep2oso5pqxzj/bafkreigtuhh5jkztpd2jbpwmsgwljrln6miskcl62es3xsgiziejo5gdve","text":"CVE-2026-121803\nThe update feature used for UFS storage devices can write data beyond its intended area because it does not check the size of a data table. This can cause the system to stop working or allow unauthorized code…\n\nToo many irrelevant or confusing CVEs? Use stackflag…","engagement":0,"posted_at":"2026-11-04T04:40:00.000Z"}],"exploit_repositories":[]}}