{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21826", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.775Z", "datePublished": "2025-03-06T16:04:32.274Z", "dateUpdated": "2026-08-05T11:54:43.241Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:43.241Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: reject mismatching sum of field_len with set key length\n\nThe field length description provides the length of each separated key\nfield in the concatenation, each field gets rounded up to 32-bits to\ncalculate the pipapo rule width from pipapo_init(). The set key length\nprovides the total size of the key aligned to 32-bits.\n\nRegister-based arithmetics still allows for combining mismatching set\nkey length and field length description, eg. set key length 10 and field\ndescription [ 5, 4 ] leading to pipapo width of 12." } ], "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 vulnerability is reached exclusively through nfnetlink/netlink configuration messages to the nf_tables subsystem (NFT_MSG_NEWSET / NFT_MSG_NEWSETELEM), which require local system access. Per kernel scoring guidance, netfilter/nftables netlink paths are Local.\nAC:L - Triggering is fully deterministic and entirely attacker-controlled: create an interval+concat set with any key length not a multiple of 4 (e.g. klen=10 with field description [5,4]) and add one ranged element. No race, no memory-layout luck, and pipapo is the only backend that accepts multi-field interval sets so the vulnerable code is always selected.\nPR:L - nfnetlink_rcv_msg() checks netlink_net_capable(skb, CAP_NET_ADMIN), which is satisfied against the network namespace's owning user namespace, so any unprivileged local user can obtain it with `unshare -Urn` and then create the malformed set. This is the standard unprivileged-user-namespace path used by public nftables exploits.\nUI:N - The attacker performs all steps themselves through netlink; no victim action, mount, or file open is needed.\nS:U - The out-of-bounds accesses and the corrupted pipapo state remain within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - pipapo consumes round_up(klen,4) bytes from buffers holding only klen, reading past the end of the heap-allocated element extension (key_end) and consuming uninitialized kernel stack bytes from the on-stack struct nft_set_elem. Those out-of-bounds values are baked into the set's lookup tables and can be recovered by an attacker probing match results through the packet path, yielding kernel heap/stack disclosure.\nI:H - Kernel data structures (the pipapo lookup and mapping tables) are populated from memory outside the intended key object, so set state is corrupted with out-of-bounds content and packet-matching verdicts, maps, and NAT decisions become dependent on that data. Consistent with kernel-CNA precedent for local nftables/ebtables out-of-bounds accesses, the memory-safety violation is treated as High integrity impact.\nA:H - The slab out-of-bounds read past the element extension is a KASAN-reportable memory-safety violation that panics on hardened/panic_on_warn configurations and can fault when the object abuts an unmapped region, and the corrupted range endpoints drive pipapo_expand() rule expansion from garbage. Any such kernel crash is scored High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_tables_api.c" ], "versions": [ { "version": "2d4c0798a1ef8db15b3277697ac2def4eda42312", "lessThan": "6b467c8feac759f4c5c86d708beca2aa2b29584f", "status": "affected", "versionType": "git" }, { "version": "77be8c495a3f841e88b46508cc20d3d7d3289da3", "lessThan": "5083a7ae45003456c253e981b30a43f71230b4a3", "status": "affected", "versionType": "git" }, { "version": "9cb084df01e198119de477ac691d682fb01e80f3", "lessThan": "2ac254343d3cf228ae0738b2615fedf85d000752", "status": "affected", "versionType": "git" }, { "version": "dc45bb00e66a33de1abb29e3d587880e1d4d9a7e", "lessThan": "82e491e085719068179ff6a5466b7387cc4bbf32", "status": "affected", "versionType": "git" }, { "version": "3ce67e3793f48c1b9635beb9bb71116ca1e51b58", "lessThan": "49b7182b97bafbd5645414aff054b4a65d05823d", "status": "affected", "versionType": "git" }, { "version": "3ce67e3793f48c1b9635beb9bb71116ca1e51b58", "lessThan": "ab50d0eff4a939d20c37721fd9766347efcdb6f6", "status": "affected", "versionType": "git" }, { "version": "3ce67e3793f48c1b9635beb9bb71116ca1e51b58", "lessThan": "1b9335a8000fb70742f7db10af314104b6ace220", "status": "affected", "versionType": "git" }, { "version": "ff67e3e488090908dc015ba04d7407d8bd467f7e", "status": "affected", "versionType": "git" }, { "version": "5.10.209", "lessThan": "5.10.235", "status": "affected", "versionType": "semver" }, { "version": "5.15.148", "lessThan": "5.15.179", "status": "affected", "versionType": "semver" }, { "version": "6.1.75", "lessThan": "6.1.129", "status": "affected", "versionType": "semver" }, { "version": "6.6.14", "lessThan": "6.6.76", "status": "affected", "versionType": "semver" }, { "version": "6.7.2", "lessThan": "6.8", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_tables_api.c" ], "versions": [ { "version": "6.8", "status": "affected" }, { "version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.129", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.76", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.13", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.2", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.209", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.148", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.75", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.14", "versionEndExcluding": "6.6.76" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.12.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.13.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6b467c8feac759f4c5c86d708beca2aa2b29584f" }, { "url": "https://git.kernel.org/stable/c/5083a7ae45003456c253e981b30a43f71230b4a3" }, { "url": "https://git.kernel.org/stable/c/2ac254343d3cf228ae0738b2615fedf85d000752" }, { "url": "https://git.kernel.org/stable/c/82e491e085719068179ff6a5466b7387cc4bbf32" }, { "url": "https://git.kernel.org/stable/c/49b7182b97bafbd5645414aff054b4a65d05823d" }, { "url": "https://git.kernel.org/stable/c/ab50d0eff4a939d20c37721fd9766347efcdb6f6" }, { "url": "https://git.kernel.org/stable/c/1b9335a8000fb70742f7db10af314104b6ace220" } ], "title": "netfilter: nf_tables: reject mismatching sum of field_len with set key length", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T20:59:57.565Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-05-12T12:03:59.800Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - BIOS", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-503939.html" } ] } ] } }