{"api_version":"1","generated_at":"2026-06-25T15:49:22+00:00","cve":"CVE-2026-53250","urls":{"html":"https://cve.report/CVE-2026-53250","api":"https://cve.report/api/cve/CVE-2026-53250.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-53250","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-53250"},"summary":{"title":"xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()\n\nThe TX metadata area resides in the UMEM buffer which is memory-mapped\nand concurrently writable by userspace. In xsk_skb_metadata(),\ncsum_start and csum_offset are read from shared memory for bounds\nvalidation, then read again for skb assignment. A malicious userspace\napplication can race to overwrite these values between the two reads,\nbypassing the bounds check and causing out-of-bounds memory access\nduring checksum computation in the transmit path.\n\nFix this by reading csum_start and csum_offset into local variables\nonce, then using the local copies for both validation and assignment.\n\nNote that other metadata fields (flags, launch_time) and the cached\ncsum fields may be mutually inconsistent due to concurrent userspace\nwrites, but this is benign: the only security-critical invariant is\nthat each field's validated value is the same one used, which local\ncaching guarantees.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-06-25 09:16:42","updated_at":"2026-06-25 09:16:42"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9","name":"https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7","name":"https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b","name":"https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53250","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53250","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 48eb03dd26304c24f03bdbb9382e89c8564e71df 0dfe05b938435892875e07771170051346412df9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 48eb03dd26304c24f03bdbb9382e89c8564e71df bfdfd2706d5fb2cd496a1506e680daf979309c8b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 48eb03dd26304c24f03bdbb9382e89c8564e71df 22ba97ea9cc1f63a0d0244fae38057ed452b6ac7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.8","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.8 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.36 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.13 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/xdp/xsk.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"0dfe05b938435892875e07771170051346412df9","status":"affected","version":"48eb03dd26304c24f03bdbb9382e89c8564e71df","versionType":"git"},{"lessThan":"bfdfd2706d5fb2cd496a1506e680daf979309c8b","status":"affected","version":"48eb03dd26304c24f03bdbb9382e89c8564e71df","versionType":"git"},{"lessThan":"22ba97ea9cc1f63a0d0244fae38057ed452b6ac7","status":"affected","version":"48eb03dd26304c24f03bdbb9382e89c8564e71df","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/xdp/xsk.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.8"},{"lessThan":"6.8","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.36","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.13","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.36","versionStartIncluding":"6.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.13","versionStartIncluding":"6.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"6.8","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()\n\nThe TX metadata area resides in the UMEM buffer which is memory-mapped\nand concurrently writable by userspace. In xsk_skb_metadata(),\ncsum_start and csum_offset are read from shared memory for bounds\nvalidation, then read again for skb assignment. A malicious userspace\napplication can race to overwrite these values between the two reads,\nbypassing the bounds check and causing out-of-bounds memory access\nduring checksum computation in the transmit path.\n\nFix this by reading csum_start and csum_offset into local variables\nonce, then using the local copies for both validation and assignment.\n\nNote that other metadata fields (flags, launch_time) and the cached\ncsum fields may be mutually inconsistent due to concurrent userspace\nwrites, but this is benign: the only security-critical invariant is\nthat each field's validated value is the same one used, which local\ncaching guarantees."}],"providerMetadata":{"dateUpdated":"2026-06-25T08:39:42.630Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9"},{"url":"https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b"},{"url":"https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7"}],"title":"xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-53250","datePublished":"2026-06-25T08:39:42.630Z","dateReserved":"2026-06-09T07:44:35.394Z","dateUpdated":"2026-06-25T08:39:42.630Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-06-25 09:16:42","lastModifiedDate":"2026-06-25 09:16:42","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"53250","Ordinal":"1","Title":"xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metad","CVE":"CVE-2026-53250","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"53250","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()\n\nThe TX metadata area resides in the UMEM buffer which is memory-mapped\nand concurrently writable by userspace. In xsk_skb_metadata(),\ncsum_start and csum_offset are read from shared memory for bounds\nvalidation, then read again for skb assignment. A malicious userspace\napplication can race to overwrite these values between the two reads,\nbypassing the bounds check and causing out-of-bounds memory access\nduring checksum computation in the transmit path.\n\nFix this by reading csum_start and csum_offset into local variables\nonce, then using the local copies for both validation and assignment.\n\nNote that other metadata fields (flags, launch_time) and the cached\ncsum fields may be mutually inconsistent due to concurrent userspace\nwrites, but this is benign: the only security-critical invariant is\nthat each field's validated value is the same one used, which local\ncaching guarantees.","Type":"Description","Title":"xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metad"}]}}}