{"cve":"CVE-2026-23243","nvd":{"published":"2026-03-18T11:16:16.090","modified":"2026-10-19T19:17:43.527","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/umad: Reject negative data_len in ib_umad_write\n\nib_umad_write computes data_len from user-controlled count and the\nMAD header sizes. With a mismatched user MAD header size and RMPP\nheader length, data_len can become negative and reach ib_create_send_mad().\nThis can make the padding calculation exceed the segment size and trigger\nan out-of-bounds memset in alloc_send_rmpp_list().\n\nAdd an explicit check to reject negative data_len before creating the\nsend buffer.\n\nKASAN splat:\n[  211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0\n[  211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102\n[  211.365867] ib_create_send_mad+0xa01/0x11b0\n[  211.365887] ib_umad_write+0x853/0x1c80","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-787","CWE-190"],"references":["https://git.kernel.org/stable/c/1371ef6b1ecf3676b8942f5dfb3634fb0648128e","https://git.kernel.org/stable/c/205955f29c26330b1dc7fdeadd5bb97c38e26f56","https://git.kernel.org/stable/c/362e45fd9069ffa1523f9f1633b606ebf72060d7","https://git.kernel.org/stable/c/52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b","https://git.kernel.org/stable/c/5551b02fdbfd85a325bb857f3a8f9c9f33397ed2"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-23243","score":0.00176,"percentile":0.07056,"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."]}