{"api_version":"1","generated_at":"2026-05-28T02:09:00+00:00","cve":"CVE-2026-45839","urls":{"html":"https://cve.report/CVE-2026-45839","api":"https://cve.report/api/cve/CVE-2026-45839.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-45839","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-45839"},"summary":{"title":"bpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()\n\nCO-RE accessor strings are colon-separated indices that describe a path\nfrom a root BTF type to a target field, e.g. \"0:1:2\" walks through\nnested struct members. bpf_core_parse_spec() parses each component with\nsscanf(\"%d\"), so negative values like -1 are silently accepted.  The\nsubsequent bounds checks (access_idx >= btf_vlen(t)) only guard the\nupper bound and always pass for negative values because C integer\npromotion converts the __u16 btf_vlen result to int, making the\ncomparison (int)(-1) >= (int)(N) false for any positive N.\n\nWhen -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,\nproducing an out-of-bounds read far past the members array.  A crafted\nBPF program with a negative CO-RE accessor on any struct that exists in\nvmlinux BTF (e.g. task_struct) crashes the kernel deterministically\nduring BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y\n(default on major distributions).  The bug is reachable with CAP_BPF:\n\n BUG: unable to handle page fault for address: ffffed11818b6626\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n Oops: Oops: 0000 [#1] SMP KASAN NOPTI\n CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)\n RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)\n RAX: 00000000ffffffff\n Call Trace:\n  <TASK>\n  bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)\n  bpf_core_apply (kernel/bpf/btf.c:9507)\n  check_core_relo (kernel/bpf/verifier.c:19475)\n  bpf_check (kernel/bpf/verifier.c:26031)\n  bpf_prog_load (kernel/bpf/syscall.c:3089)\n  __sys_bpf (kernel/bpf/syscall.c:6228)\n  </TASK>\n\nCO-RE accessor indices are inherently non-negative (struct member index,\narray element index, or enumerator index), so reject them immediately\nafter parsing.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-27 11:16:23","updated_at":"2026-05-27 14:48:03"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/3ff85ae79e1a74baeb916b78a63d821f6d19a994","name":"https://git.kernel.org/stable/c/3ff85ae79e1a74baeb916b78a63d821f6d19a994","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/99dbab7b5a12d8f58d5b0aa2f7a1fe656a70f4b2","name":"https://git.kernel.org/stable/c/99dbab7b5a12d8f58d5b0aa2f7a1fe656a70f4b2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a","name":"https://git.kernel.org/stable/c/36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/76f2ebaf79a9ae6d0737b87f045fe769e425d78f","name":"https://git.kernel.org/stable/c/76f2ebaf79a9ae6d0737b87f045fe769e425d78f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1c22483a2c4bbf747787f328392ca3e68619c4dc","name":"https://git.kernel.org/stable/c/1c22483a2c4bbf747787f328392ca3e68619c4dc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-45839","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45839","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ddc7c3042614e273044f698d2beab25cc3842d45 3ff85ae79e1a74baeb916b78a63d821f6d19a994 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ddc7c3042614e273044f698d2beab25cc3842d45 36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ddc7c3042614e273044f698d2beab25cc3842d45 76f2ebaf79a9ae6d0737b87f045fe769e425d78f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ddc7c3042614e273044f698d2beab25cc3842d45 99dbab7b5a12d8f58d5b0aa2f7a1fe656a70f4b2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ddc7c3042614e273044f698d2beab25cc3842d45 1c22483a2c4bbf747787f328392ca3e68619c4dc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.4","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.4 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.141 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.91 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.33 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.10 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"45839","cve":"CVE-2026-45839","epss":"0.000150000","percentile":"0.035310000","score_date":"2026-05-27","updated_at":"2026-05-28 00:02:12"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["tools/lib/bpf/relo_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"3ff85ae79e1a74baeb916b78a63d821f6d19a994","status":"affected","version":"ddc7c3042614e273044f698d2beab25cc3842d45","versionType":"git"},{"lessThan":"36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a","status":"affected","version":"ddc7c3042614e273044f698d2beab25cc3842d45","versionType":"git"},{"lessThan":"76f2ebaf79a9ae6d0737b87f045fe769e425d78f","status":"affected","version":"ddc7c3042614e273044f698d2beab25cc3842d45","versionType":"git"},{"lessThan":"99dbab7b5a12d8f58d5b0aa2f7a1fe656a70f4b2","status":"affected","version":"ddc7c3042614e273044f698d2beab25cc3842d45","versionType":"git"},{"lessThan":"1c22483a2c4bbf747787f328392ca3e68619c4dc","status":"affected","version":"ddc7c3042614e273044f698d2beab25cc3842d45","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["tools/lib/bpf/relo_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.4"},{"lessThan":"5.4","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.141","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.91","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.33","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.10","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.141","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.91","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.33","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.10","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc1","versionStartIncluding":"5.4","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()\n\nCO-RE accessor strings are colon-separated indices that describe a path\nfrom a root BTF type to a target field, e.g. \"0:1:2\" walks through\nnested struct members. bpf_core_parse_spec() parses each component with\nsscanf(\"%d\"), so negative values like -1 are silently accepted.  The\nsubsequent bounds checks (access_idx >= btf_vlen(t)) only guard the\nupper bound and always pass for negative values because C integer\npromotion converts the __u16 btf_vlen result to int, making the\ncomparison (int)(-1) >= (int)(N) false for any positive N.\n\nWhen -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,\nproducing an out-of-bounds read far past the members array.  A crafted\nBPF program with a negative CO-RE accessor on any struct that exists in\nvmlinux BTF (e.g. task_struct) crashes the kernel deterministically\nduring BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y\n(default on major distributions).  The bug is reachable with CAP_BPF:\n\n BUG: unable to handle page fault for address: ffffed11818b6626\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n Oops: Oops: 0000 [#1] SMP KASAN NOPTI\n CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)\n RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)\n RAX: 00000000ffffffff\n Call Trace:\n  <TASK>\n  bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)\n  bpf_core_apply (kernel/bpf/btf.c:9507)\n  check_core_relo (kernel/bpf/verifier.c:19475)\n  bpf_check (kernel/bpf/verifier.c:26031)\n  bpf_prog_load (kernel/bpf/syscall.c:3089)\n  __sys_bpf (kernel/bpf/syscall.c:6228)\n  </TASK>\n\nCO-RE accessor indices are inherently non-negative (struct member index,\narray element index, or enumerator index), so reject them immediately\nafter parsing."}],"providerMetadata":{"dateUpdated":"2026-05-27T09:24:37.855Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/3ff85ae79e1a74baeb916b78a63d821f6d19a994"},{"url":"https://git.kernel.org/stable/c/36a9012f76ba8d9189ae56a1f8bb7c87c07a1f3a"},{"url":"https://git.kernel.org/stable/c/76f2ebaf79a9ae6d0737b87f045fe769e425d78f"},{"url":"https://git.kernel.org/stable/c/99dbab7b5a12d8f58d5b0aa2f7a1fe656a70f4b2"},{"url":"https://git.kernel.org/stable/c/1c22483a2c4bbf747787f328392ca3e68619c4dc"}],"title":"bpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-45839","datePublished":"2026-05-27T09:24:37.855Z","dateReserved":"2026-05-13T15:03:33.077Z","dateUpdated":"2026-05-27T09:24:37.855Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 11:16:23","lastModifiedDate":"2026-05-27 14:48:03","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"45839","Ordinal":"1","Title":"bpf: reject negative CO-RE accessor indices in bpf_core_parse_sp","CVE":"CVE-2026-45839","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"45839","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject negative CO-RE accessor indices in bpf_core_parse_spec()\n\nCO-RE accessor strings are colon-separated indices that describe a path\nfrom a root BTF type to a target field, e.g. \"0:1:2\" walks through\nnested struct members. bpf_core_parse_spec() parses each component with\nsscanf(\"%d\"), so negative values like -1 are silently accepted.  The\nsubsequent bounds checks (access_idx >= btf_vlen(t)) only guard the\nupper bound and always pass for negative values because C integer\npromotion converts the __u16 btf_vlen result to int, making the\ncomparison (int)(-1) >= (int)(N) false for any positive N.\n\nWhen -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,\nproducing an out-of-bounds read far past the members array.  A crafted\nBPF program with a negative CO-RE accessor on any struct that exists in\nvmlinux BTF (e.g. task_struct) crashes the kernel deterministically\nduring BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y\n(default on major distributions).  The bug is reachable with CAP_BPF:\n\n BUG: unable to handle page fault for address: ffffed11818b6626\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n Oops: Oops: 0000 [#1] SMP KASAN NOPTI\n CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)\n RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)\n RAX: 00000000ffffffff\n Call Trace:\n  <TASK>\n  bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)\n  bpf_core_apply (kernel/bpf/btf.c:9507)\n  check_core_relo (kernel/bpf/verifier.c:19475)\n  bpf_check (kernel/bpf/verifier.c:26031)\n  bpf_prog_load (kernel/bpf/syscall.c:3089)\n  __sys_bpf (kernel/bpf/syscall.c:6228)\n  </TASK>\n\nCO-RE accessor indices are inherently non-negative (struct member index,\narray element index, or enumerator index), so reject them immediately\nafter parsing.","Type":"Description","Title":"bpf: reject negative CO-RE accessor indices in bpf_core_parse_sp"}]}}}