{"cve":"CVE-2026-98132","nvd":{"published":"2026-09-25T11:17:44.603","modified":"2026-10-19T10:18:12.373","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: don't downgrade half-dead scalar zero spills to STACK_ZERO\n\nstates.c:__clean_func_state() can downgrade scalar zero spill to\nSTACK_ZERO in the following case:\n\n  *(u64 *)(r10 - 8) = 0;\n  ... checkpoint ...\n  r1 = *(u32 *)(r10 - 4);\n  ... no reads from r10-8 ...\n\nHere 4 bytes at r10-8 are dead and verifier changes scalar spill to a\ncombination: 0000pppp (p stands for poison). Such a change breaks\nprecision propagation chains. All places that produce STACK_ZERO\nshould call bpf_mark_chain_precision() for the zero source.\n\nThis patch fixes the bug in a simplest way possible:\navoids converting stack spills of zero to STACK_ZERO.\nTwo smarter approaches are possible:\n- do bpf_mark_chain_precision() from __clean_func_state()\n- check slot liveness information in check_stack_write_fixed_off()\n\nI investigated both and the changes required are a bit tricky,\nhence go with a simple fix for the time being.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/2f3536bff8823d3c5fdbbe15e17bfca696cc2b2e","https://git.kernel.org/stable/c/436fa689630b741a77ef8c4a6f426479affd5bac"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-98132","score":0.00108,"percentile":0.01179,"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."]}