{"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"}}}}