{"api_version":"1","generated_at":"2026-07-24T19:45:26+00:00","cve":"CVE-2026-23254","urls":{"html":"https://cve.report/CVE-2026-23254","api":"https://cve.report/api/cve/CVE-2026-23254.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-23254","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-23254"},"summary":{"title":"net: gro: fix outer network offset","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gro: fix outer network offset\n\nThe udp GRO complete stage assumes that all the packets inserted the RX\nhave the `encapsulation` flag zeroed. Such assumption is not true, as a\nfew H/W NICs can set such flag when H/W offloading the checksum for\nan UDP encapsulated traffic, the tun driver can inject GSO packets with\nUDP encapsulation and the problematic layout can also be created via\na veth based setup.\n\nDue to the above, in the problematic scenarios, udp4_gro_complete() uses\nthe wrong network offset (inner instead of outer) to compute the outer\nUDP header pseudo checksum, leading to csum validation errors later on\nin packet processing.\n\nAddress the issue always clearing the encapsulation flag at GRO completion\ntime. Such flag will be set again as needed for encapsulated packets by\nudp_gro_complete().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-03-18 18:16:23","updated_at":"2026-06-01 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Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23254","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected af276a5ac8e938c8b058e3e124073cc1e322d98b 9d40a85138568696387ef04cd004c64612a70874 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 b83557bc6f560433fe5d727e241069f8db5ba709 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 2e5edb69e5d0e23ef248c56fc977039268c77a7b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 5c2c3c38be396257a6a2e55bd601a12bb9781507 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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Such assumption is not true, as a\nfew H/W NICs can set such flag when H/W offloading the checksum for\nan UDP encapsulated traffic, the tun driver can inject GSO packets with\nUDP encapsulation and the problematic layout can also be created via\na veth based setup.\n\nDue to the above, in the problematic scenarios, udp4_gro_complete() uses\nthe wrong network offset (inner instead of outer) to compute the outer\nUDP header pseudo checksum, leading to csum validation errors later on\nin packet processing.\n\nAddress the issue always clearing the encapsulation flag at GRO completion\ntime. Such flag will be set again as needed for encapsulated packets by\nudp_gro_complete().","Type":"Description","Title":"net: gro: fix outer network offset"}]}}}