{"cve":"CVE-2024-26851","nvd":{"published":"2024-04-17T11:15:08.473","modified":"2026-10-15T01:17:25.280","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_h323: Add protection for bmp length out of range\n\nUBSAN load reports an exception of BRK#5515 SHIFT_ISSUE:Bitwise shifts\nthat are out of bounds for their data type.\n\nvmlinux   get_bitmap(b=75) + 712\n<net/netfilter/nf_conntrack_h323_asn1.c:0>\nvmlinux   decode_seq(bs=0xFFFFFFD008037000, f=0xFFFFFFD008037018, level=134443100) + 1956\n<net/netfilter/nf_conntrack_h323_asn1.c:592>\nvmlinux   decode_choice(base=0xFFFFFFD0080370F0, level=23843636) + 1216\n<net/netfilter/nf_conntrack_h323_asn1.c:814>\nvmlinux   decode_seq(f=0xFFFFFFD0080371A8, level=134443500) + 812\n<net/netfilter/nf_conntrack_h323_asn1.c:576>\nvmlinux   decode_choice(base=0xFFFFFFD008037280, level=0) + 1216\n<net/netfilter/nf_conntrack_h323_asn1.c:814>\nvmlinux   DecodeRasMessage() + 304\n<net/netfilter/nf_conntrack_h323_asn1.c:833>\nvmlinux   ras_help() + 684\n<net/netfilter/nf_conntrack_h323_main.c:1728>\nvmlinux   nf_confirm() + 188\n<net/netfilter/nf_conntrack_proto.c:137>\n\nDue to abnormal data in skb->data, the extension bitmap length\nexceeds 32 when decoding ras message then uses the length to make\na shift operation. It will change into negative after several loop.\nUBSAN load could detect a negative shift as an undefined behaviour\nand reports exception.\nSo we add the protection to avoid the length exceeding 32. Or else\nit will return out of range error and stop decoding.","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":["CWE-787"],"references":["https://git.kernel.org/stable/c/014a807f1cc9c9d5173c1cd935835553b00d211c","https://git.kernel.org/stable/c/39001e3c42000e7c2038717af0d33c32319ad591","https://git.kernel.org/stable/c/4bafcc43baf7bcf93566394dbd15726b5b456b7a","https://git.kernel.org/stable/c/767146637efc528b5e3d31297df115e85a2fd362","https://git.kernel.org/stable/c/80ee5054435a11c87c9a4f30f1ff750080c96416"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:48:32.179249784+00:00"},"epss":{"cve":"CVE-2024-26851","score":0.00741,"percentile":0.54362,"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."]}