{"cve":"CVE-2026-98033","nvd":{"published":"2026-09-25T11:17:32.003","modified":"2026-10-21T13:21:19.500","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve inner map identity in callback frames\n\nCallback frame constructors initialize map-typed argument registers with\n__mark_reg_known_zero() and then restore map_ptr. This clears map_uid,\nwhich is the only field distinguishing inner maps that share an\ninner_map_meta template.\n\nWhen a timer callback invokes bpf_for_each_map_elem() on a second inner\nmap, both the saved first map and the second map value can reach the nested\ncallback as the same template with map_uid zero. bpf_timer_init() then\naccepts pairing the timer from the second map with the first map.\n\nThe runtime records the first map in the timer without taking a reference.\nFreeing that map does not find the timer stored in the second map, so a\nlater timer callback dereferences the freed map.\n\nCopy map_uid from the same caller register as map_ptr when constructing\nfor-each, timer/workqueue, and task-work callback arguments. The existing\nidentity check can then reject mismatched inner maps while allowing a\ncallback value to be paired with its actual map.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/08b534bafdd9de65b6374474a8fe719c90eb3b01","https://git.kernel.org/stable/c/166221c52d3ca332f8699a854efca8e2704bb137","https://git.kernel.org/stable/c/66ff2eff093d2a0838f39c713eeb590bc0946c2a","https://git.kernel.org/stable/c/b90c5d770dad910fb89e6c1b15052a8a1e8db752","https://git.kernel.org/stable/c/cf85e4f94d7feef8b3c4c90dbe2468595a48393b"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-98033","score":0.002,"percentile":0.09801,"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."]}