{"api_version":"1","generated_at":"2026-06-01T01:19:24+00:00","cve":"CVE-2026-45886","urls":{"html":"https://cve.report/CVE-2026-45886","api":"https://cve.report/api/cve/CVE-2026-45886.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-45886","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-45886"},"summary":{"title":"bpf: Fix bpf_xdp_store_bytes proto for read-only arg","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix bpf_xdp_store_bytes proto for read-only arg\n\nWhile making some maps in Cilium read-only from the BPF side, we noticed\nthat the bpf_xdp_store_bytes proto is incorrect. In particular, the\nverifier was throwing the following error:\n\n  ; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr),\n                          &nat->address, 4, 0);\n  635: (79) r1 = *(u64 *)(r10 -144)     ; R1=ctx() R10=fp0 fp-144=ctx()\n  636: (b4) w2 = 26                     ; R2=26\n  637: (b4) w4 = 4                      ; R4=4\n  638: (b4) w5 = 0                      ; R5=0\n  639: (85) call bpf_xdp_store_bytes#190\n  write into map forbidden, value_size=6 off=0 size=4\n\nnat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE.\nThe verifier checks the helper's memory access to R3 in\ncheck_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third\nargument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the\nMEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3.\nGiven R3 points to a read-only map, the check fails.\n\nConversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading\nfrom uninitialized memory.\n\nThis patch simply fixes the expected argument type to match that of\nbpf_skb_store_bytes.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-27 14:17:02","updated_at":"2026-05-27 14:48:31"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52","name":"https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f","name":"https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e","name":"https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775","name":"https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15","name":"https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b","name":"https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-45886","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45886","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f364222d032eea6b245780e845ad213dab28cdd ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f364222d032eea6b245780e845ad213dab28cdd ddc34a1b85505c919026ddc82fafdada9a160b15 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f364222d032eea6b245780e845ad213dab28cdd 0db169a91381a473b7974021d1c02f8da72c5775 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f364222d032eea6b245780e845ad213dab28cdd d7b87adeb0eb539b9b824b101bb14fb01e41240b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f364222d032eea6b245780e845ad213dab28cdd 57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3f364222d032eea6b245780e845ad213dab28cdd 6557f1565d779851c4db9c488c49c05a47a6e72f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.18","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.18 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.165 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.128 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.75 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.14 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.4 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"45886","cve":"CVE-2026-45886","epss":"0.000240000","percentile":"0.073730000","score_date":"2026-05-31","updated_at":"2026-06-01 00:08:19"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/core/filter.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e","status":"affected","version":"3f364222d032eea6b245780e845ad213dab28cdd","versionType":"git"},{"lessThan":"ddc34a1b85505c919026ddc82fafdada9a160b15","status":"affected","version":"3f364222d032eea6b245780e845ad213dab28cdd","versionType":"git"},{"lessThan":"0db169a91381a473b7974021d1c02f8da72c5775","status":"affected","version":"3f364222d032eea6b245780e845ad213dab28cdd","versionType":"git"},{"lessThan":"d7b87adeb0eb539b9b824b101bb14fb01e41240b","status":"affected","version":"3f364222d032eea6b245780e845ad213dab28cdd","versionType":"git"},{"lessThan":"57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52","status":"affected","version":"3f364222d032eea6b245780e845ad213dab28cdd","versionType":"git"},{"lessThan":"6557f1565d779851c4db9c488c49c05a47a6e72f","status":"affected","version":"3f364222d032eea6b245780e845ad213dab28cdd","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/core/filter.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.18"},{"lessThan":"5.18","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.165","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.128","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.75","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.14","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.165","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.128","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.75","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.14","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.4","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"5.18","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix bpf_xdp_store_bytes proto for read-only arg\n\nWhile making some maps in Cilium read-only from the BPF side, we noticed\nthat the bpf_xdp_store_bytes proto is incorrect. In particular, the\nverifier was throwing the following error:\n\n  ; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr),\n                          &nat->address, 4, 0);\n  635: (79) r1 = *(u64 *)(r10 -144)     ; R1=ctx() R10=fp0 fp-144=ctx()\n  636: (b4) w2 = 26                     ; R2=26\n  637: (b4) w4 = 4                      ; R4=4\n  638: (b4) w5 = 0                      ; R5=0\n  639: (85) call bpf_xdp_store_bytes#190\n  write into map forbidden, value_size=6 off=0 size=4\n\nnat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE.\nThe verifier checks the helper's memory access to R3 in\ncheck_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third\nargument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the\nMEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3.\nGiven R3 points to a read-only map, the check fails.\n\nConversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading\nfrom uninitialized memory.\n\nThis patch simply fixes the expected argument type to match that of\nbpf_skb_store_bytes."}],"providerMetadata":{"dateUpdated":"2026-05-27T12:16:58.000Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e"},{"url":"https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15"},{"url":"https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775"},{"url":"https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b"},{"url":"https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52"},{"url":"https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f"}],"title":"bpf: Fix bpf_xdp_store_bytes proto for read-only arg","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-45886","datePublished":"2026-05-27T12:16:58.000Z","dateReserved":"2026-05-13T15:03:33.082Z","dateUpdated":"2026-05-27T12:16:58.000Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 14:17:02","lastModifiedDate":"2026-05-27 14:48:31","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"45886","Ordinal":"1","Title":"bpf: Fix bpf_xdp_store_bytes proto for read-only arg","CVE":"CVE-2026-45886","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"45886","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix bpf_xdp_store_bytes proto for read-only arg\n\nWhile making some maps in Cilium read-only from the BPF side, we noticed\nthat the bpf_xdp_store_bytes proto is incorrect. In particular, the\nverifier was throwing the following error:\n\n  ; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr),\n                          &nat->address, 4, 0);\n  635: (79) r1 = *(u64 *)(r10 -144)     ; R1=ctx() R10=fp0 fp-144=ctx()\n  636: (b4) w2 = 26                     ; R2=26\n  637: (b4) w4 = 4                      ; R4=4\n  638: (b4) w5 = 0                      ; R5=0\n  639: (85) call bpf_xdp_store_bytes#190\n  write into map forbidden, value_size=6 off=0 size=4\n\nnat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE.\nThe verifier checks the helper's memory access to R3 in\ncheck_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third\nargument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the\nMEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3.\nGiven R3 points to a read-only map, the check fails.\n\nConversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading\nfrom uninitialized memory.\n\nThis patch simply fixes the expected argument type to match that of\nbpf_skb_store_bytes.","Type":"Description","Title":"bpf: Fix bpf_xdp_store_bytes proto for read-only arg"}]}}}