{"cve":"CVE-2026-98590","nvd":{"published":"2026-10-18T16:17:11.610","modified":"2026-10-19T10:19:20.057","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix bpf_sock context code generation\n\nCurrently, the ctx access code reads the rx_queue_mapping\nfield with either a 4-byte or 2-byte load. The rest of the bits\nin the register are marked known zero by the verifier. However,\nthe emitted ctx access code places in the register on certain\nthe special value (-1) using BPF_MOV_IMM64, which gets sign-extended\nto turn on all the bits in the register. By shifting this value right,\nthe program ends up with a value at runtime above what the verifier\nassumes is possible.\n\nFix this by ensuring the read value is as wide as the assumed size.\nUse MOV32 instructions instead of MOV64 instructions to keep\nthe upper bits zero as assumed by the verifier. Also properly report\nthe size of the destination variable (the bpf_sock field, 4 bytes) instead\nof the source (the socket field, 2 bytes).","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/4a41d064facc3330e176ecbbf5b0026ed18a5c69","https://git.kernel.org/stable/c/4a4852376e3a2727ea40e61143d6d7c22bb6dfad","https://git.kernel.org/stable/c/70288599d1754e157df8326239316dbdf08ea33c","https://git.kernel.org/stable/c/84ebb991ae985149079ae9ab51b7e3ba25a9ff53","https://git.kernel.org/stable/c/b3f37afc7fd7c52bc2114310aff1eb24c7cd4d73"],"products":[],"source":"nvd","synced_at":"2026-10-19T23:00:53.604569364+00:00"},"epss":{"cve":"CVE-2026-98590","score":0.00216,"percentile":0.11955,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}