--- id: CVE-2025-21826 title: |- In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: reject mismatching sum of field_len with set key length The field length description provides the length of each separated key field in the conca… summary: |- In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: reject mismatching sum of field_len with set key length The field length description provides the length of each separated key field in the conca… severity: high cvss: 7.8 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H' vendor: linux product: linux_kernel affected: - 'linux_kernel >= 5.10.209, < 5.10.235' - 'linux_kernel >= 5.15.148, < 5.15.179' - 'linux_kernel >= 6.1.75, < 6.1.129' - 'linux_kernel >= 6.6.14, < 6.6.76' - 'linux_kernel >= 6.7.2, < 6.12.13' - 'linux_kernel >= 6.13, < 6.13.2' patched: - linux_kernel 6.13.2 published: '2025-03-06' updated: '2026-07-30' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21826' references: - url: 'https://git.kernel.org/stable/c/1b9335a8000fb70742f7db10af314104b6ace220' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/2ac254343d3cf228ae0738b2615fedf85d000752' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/49b7182b97bafbd5645414aff054b4a65d05823d' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/5083a7ae45003456c253e981b30a43f71230b4a3' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/6b467c8feac759f4c5c86d708beca2aa2b29584f' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/82e491e085719068179ff6a5466b7387cc4bbf32' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/ab50d0eff4a939d20c37721fd9766347efcdb6f6' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-503939.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-21826.json - url: 'https://access.redhat.com/security/cve/CVE-2025-21826' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2350392' - url: 'https://www.cve.org/CVERecord?id=CVE-2025-21826' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21826' - url: >- https://lore.kernel.org/linux-cve-announce/2025030630-CVE-2025-21826-c263@gregkh/T - url: 'https://access.redhat.com/errata/RHSA-2025:20095' - url: 'https://access.redhat.com/errata/RHSA-2026:70484' - url: 'https://access.redhat.com/errata/RHSA-2025:20518' tags: - nvd - csaf - vex - red-hat epss: 0.00196 epssPercentile: 0.08321 ingestedAt: '2026-07-30T06:53:10.248Z' cwe: - CWE-682 scores: nvd: 7.8 vendor: 6.1 --- ## Overview In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: reject mismatching sum of field_len with set key length The field length description provides the length of each separated key field in the concatenation, each field gets rounded up to 32-bits to calculate the pipapo rule width from pipapo_init(). The set key length provides the total size of the key aligned to 32-bits. Register-based arithmetics still allows for combining mismatching set key length and field length description, eg. set key length 10 and field description [ 5, 4 ] leading to pipapo width of 12. ## Affected - `linux_kernel >= 5.10.209, < 5.10.235` - `linux_kernel >= 5.15.148, < 5.15.179` - `linux_kernel >= 6.1.75, < 6.1.129` - `linux_kernel >= 6.6.14, < 6.6.76` - `linux_kernel >= 6.7.2, < 6.12.13` - `linux_kernel >= 6.13, < 6.13.2` ## Remediation Upgrade past the affected range: - `linux_kernel 6.13.2` ## Vendor advisories - **RHSA-2025:20095** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2025-11-11 · [advisory](https://access.redhat.com/errata/RHSA-2025:20095) - **RHSA-2026:70484** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6), Red Hat Enterprise Linux Real Time EUS (v.9.6) · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70484) - **RHSA-2025:20518** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2025-11-11 · [advisory](https://access.redhat.com/errata/RHSA-2025:20518) - **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-21826.json)