{"id":"CVE-2026-99999","published":"2026-10-15T13:17:14Z","modified":"2026-10-19T22:17:28Z","title":"In the Linux kernel, the following vulnerability has been resolved: ipv4: validate checksum_start before completing…","vendor":"Linux","product":"Linux","tier":"core","eol":null,"description":{"text":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: validate checksum_start before completing checksum\n\nIf a packet with bad checksum metadata gets into the ipv4 stack,\nskb_checksum_help can corrupt the network header and cause a bunch of\nmischief.\n\nThis was discovered and reported by Paulos, and has been reporoduced\nby others independently since.\n\nWe really shouldn't allow such packets in, but as a defence\nin depth measure, let's also check before we complete the checksum.\n\nA more complete validation at input is forthcoming, but needs more work.","provenance":"source","from":"NVD"},"summary":{"text":"A critical improper input validation vulnerability in the Linux kernel allows packets with bad checksum metadata to corrupt the network header via skb_checksum_help. Linux kernel users are affected.","provenance":"ai","model":"deepseek-v4-flash","generatedAt":"2026-10-23T03:21:07Z"},"cvss":{"score":9.3,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.00788,"percentile":0.5615,"date":"2026-10-30","provenance":"source"},"kev":null,"vulncheckKev":{"dateAdded":"2026-10-19","exploitedFirstSeen":"2026-10-19","ransomware":false,"evidence":[{"url":"https://access.redhat.com/security/cve/cve-2026-99999","date":"2026-10-19"}],"evidenceTotal":1,"provenance":"source"},"exploited":true,"otx":{"pulseCount":11,"pulses":[{"name":"SUSE Ships Another Kernel Update Closing Twenty Seven New Linux Flaws","url":"https://otx.alienvault.com/pulse/6ae3e9d1d7a5bcf3391c4cee","created":"2026-10-30"},{"name":"Known_Cve | Oct 24, 2026 | Part 1/3","url":"https://otx.alienvault.com/pulse/6adb7414397c3ad4799aa4ce","created":"2026-10-23"},{"name":"Known_Cve | Oct 23, 2026 | Part 1/3","url":"https://otx.alienvault.com/pulse/6ada23770d71749da2321a29","created":"2026-10-22"},{"name":"Known_Cve | Oct 22, 2026 | Part 2/4","url":"https://otx.alienvault.com/pulse/6ad8d3466c8181f05516bab7","created":"2026-10-21"},{"name":"Known_Cve | Oct 21, 2026 | Part 3/4","url":"https://otx.alienvault.com/pulse/6ad78144340f998d3db4d0bc","created":"2026-10-20"},{"name":"Known_Cve | Oct 20, 2026 | Part 3/4","url":"https://otx.alienvault.com/pulse/6ad62f761b14c745b837b947","created":"2026-10-19"},{"name":"Known_Cve | Oct 19, 2026 | Part 3/4","url":"https://otx.alienvault.com/pulse/6ad4ddb44d734735b605dc2f","created":"2026-10-18"},{"name":"Known_Cve | Oct 18, 2026 | Part 3/4","url":"https://otx.alienvault.com/pulse/6ad38c34c49c0273168a0f7d","created":"2026-10-17"},{"name":"Known_Cve | Oct 17, 2026 | Part 3/4","url":"https://otx.alienvault.com/pulse/6ad23abd6cb9332fcbb88e3b","created":"2026-10-16"},{"name":"Known_Cve | Oct 16, 2026 | Part 3/3","url":"https://otx.alienvault.com/pulse/6ad0e94086fc75fcda994436","created":"2026-10-15"}],"provenance":"machine"},"cwes":[{"id":"CWE-20","name":"Improper Input Validation"}],"references":[{"url":"https://git.kernel.org/stable/c/0fab003ef4698e0628060a45a48f14b43ba2a40a","tags":[]},{"url":"https://git.kernel.org/stable/c/32a8b0adaa18e52aaa0b246b5ffe683075354dbb","tags":[]},{"url":"https://git.kernel.org/stable/c/6785011f8b16abf40b1e9d8b2e332232b3e68822","tags":[]},{"url":"https://git.kernel.org/stable/c/94524b7b32691de2e2ce162c04d6cbc9106e5cbf","tags":[]},{"url":"https://git.kernel.org/stable/c/a464d950f31c89565cbaae038cc60db04fe01956","tags":[]},{"url":"https://git.kernel.org/stable/c/a65f69e0f38ffbed1b128029e09097436416dc8b","tags":[]},{"url":"https://git.kernel.org/stable/c/c3e33464746166264334641dc850a36eef7e6326","tags":[]},{"url":"https://git.kernel.org/stable/c/f3e835af6226f1dd12160cbd696081e9b6155de0","tags":[]},{"url":"https://pwn.ai/blog/pwnescape","tags":[]},{"url":"https://vercel.com/blog/findings-from-the-1-million-dollar-vercel-sandbox-challenge","tags":[]},{"url":"http://www.openwall.com/lists/oss-security/2026/10/15/5","tags":[]}],"techniques":[],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-102044","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-102044","exploited":false,"exploitedSince":null,"provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":10,"skipped":4,"earliest":"2026-10-16","earliestUrl":"https://github.com/MChorfa/csumguard","repos":[{"name":"PeronGH/CVE-2026-99999","url":"https://github.com/PeronGH/CVE-2026-99999","stars":20,"created":"2026-10-17"},{"name":"01luyicheng/CVE-2026-99999","url":"https://github.com/01luyicheng/CVE-2026-99999","stars":5,"created":"2026-10-18"},{"name":"MChorfa/csumguard","url":"https://github.com/MChorfa/csumguard","stars":2,"created":"2026-10-16"},{"name":"Quaerendir/cve-2026-99999-audit","url":"https://github.com/Quaerendir/cve-2026-99999-audit","stars":2,"created":"2026-10-17"},{"name":"gandli/CVE-2026-99999-pwnescape","url":"https://github.com/gandli/CVE-2026-99999-pwnescape","stars":2,"created":"2026-10-19"}]},"first":{"date":"2026-10-16","source":"PoC-in-GitHub","url":"https://github.com/MChorfa/csumguard"},"provenance":"source"},"exploitRefs":[],"flow":[],"timeline":[{"date":"2026-10-15","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99999","provenance":"source"},{"date":"2026-10-16","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/MChorfa/csumguard","provenance":"source"},{"date":"2026-10-19","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://access.redhat.com/security/cve/cve-2026-99999","provenance":"source"}],"speed":{"daysToPublicExploit":1,"firstExploitFrom":"PoC-in-GitHub","daysToKev":null},"priority":{"score":70.2,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in VulnCheck KEV"},{"name":"Recent KEV listing","points":10.0,"detail":"added 12 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":11.23,"detail":"percentile 0.5615"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"10 PoC-in-GitHub repos"},{"name":"Mentioned in OTX pulses","points":2.45,"detail":"11 pulses"},{"name":"CVSS severity","points":6.51,"detail":"base score 9.3"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}