{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31413", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.087Z", "datePublished": "2026-04-12T05:36:14.632Z", "dateUpdated": "2026-08-05T12:22:19.762Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:22:19.762Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR\n\nmaybe_fork_scalars() is called for both BPF_AND and BPF_OR when the\nsource operand is a constant. When dst has signed range [-1, 0], it\nforks the verifier state: the pushed path gets dst = 0, the current\npath gets dst = -1.\n\nFor BPF_AND this is correct: 0 & K == 0.\nFor BPF_OR this is wrong: 0 | K == K, not 0.\n\nThe pushed path therefore tracks dst as 0 when the runtime value is K,\nproducing an exploitable verifier/runtime divergence that allows\nout-of-bounds map access.\n\nFix this by passing env->insn_idx (instead of env->insn_idx + 1) to\npush_stack(), so the pushed path re-executes the ALU instruction with\ndst = 0 and naturally computes the correct result for any opcode." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable verifier path is reached through the local bpf() syscall during BPF_PROG_LOAD, not through a remote protocol. A plausible path is an attacker-supplied socket-filter BPF program using attacker-created maps.\nAC:L - The attacker controls the BPF bytecode, map layout, and scalar values needed to trigger the verifier/runtime divergence. There is no race or external condition beyond attacker control.\nPR:L - Exploitation requires a local user able to load BPF programs, which can be a basic unprivileged user where unprivileged BPF is enabled or a delegated BPF capability path exists. It does not inherently require real init-namespace root for the vulnerable verifier logic.\nUI:N - No victim action is required after the attacker loads and runs the crafted BPF program. The trigger is fully under the local attacker's control.\nS:U - This is a standard kernel privilege-escalation style BPF verifier flaw within the same host kernel security authority. It does not cross a VM, hypervisor, or IOMMU boundary.\nC:H - The verifier/runtime divergence allows out-of-bounds map-value reads, which can expose adjacent kernel heap data and be developed into broader kernel memory disclosure. BPF verifier OOB map-access bugs are commonly exploitable as kernel read primitives.\nI:H - The same incorrect bounds reasoning can be applied to writes through map-value pointers, enabling out-of-bounds kernel heap corruption. That is sufficient for arbitrary kernel memory modification or code execution in a defensible worst case.\nA:H - Out-of-bounds BPF memory access can corrupt kernel memory or fault the kernel, causing an oops, panic, or hang. Even failed exploitation can be repeatedly triggered by the local attacker." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "dea9989a3f3961faede93752cd81eb5a9514d911", "lessThan": "342aa1ee995ef5bbf876096dc3a5e51218d76fa4", "status": "affected", "versionType": "git" }, { "version": "4c122e8ae14950cf6b59d208fc5160f7c601e746", "lessThan": "58bd87d0e69204dbd739e4387a1edb0c4b1644e7", "status": "affected", "versionType": "git" }, { "version": "e52567173ba86dbffb990595fbe60e2e83899372", "lessThan": "d13281ae7ea8902b21d99d10a2c8caf0bdec0455", "status": "affected", "versionType": "git" }, { "version": "bffacdb80b93b7b5e96b26fad64cc490a6c7d6c7", "lessThan": "c845894ebd6fb43226b3118d6b017942550910c5", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "6.12.75", "lessThan": "6.12.80", "status": "affected", "versionType": "semver" }, { "version": "6.18.16", "lessThan": "6.18.21", "status": "affected", "versionType": "semver" }, { "version": "6.19.6", "lessThan": "6.19.11", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.75", "versionEndExcluding": "6.12.80" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.16", "versionEndExcluding": "6.18.21" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19.6", "versionEndExcluding": "6.19.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/342aa1ee995ef5bbf876096dc3a5e51218d76fa4" }, { "url": "https://git.kernel.org/stable/c/58bd87d0e69204dbd739e4387a1edb0c4b1644e7" }, { "url": "https://git.kernel.org/stable/c/d13281ae7ea8902b21d99d10a2c8caf0bdec0455" }, { "url": "https://git.kernel.org/stable/c/c845894ebd6fb43226b3118d6b017942550910c5" } ], "title": "bpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR", "x_generator": { "engine": "bippy-1.2.0" } } } }