{"id":"CVE-2026-68123","summary":"openvswitch: fix GSO userspace truncation underflow","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nopenvswitch: fix GSO userspace truncation underflow\n\nOVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb\nlength in OVS_CB(skb)-\u003ecutlen. When a later userspace action segments a\nGSO skb, queue_gso_packets() reuses that delta for each smaller segment.\nA segment can then reach queue_userspace_packet() with cutlen greater\nthan skb-\u003elen, underflowing the length passed to skb_zerocopy().\n\nStore the maximum preserved length instead and bound each consumer\nagainst the current skb length. Use U32_MAX as the no-truncation\nsentinel so the value remains valid if skb geometry changes before a\nconsumer handles it.","modified":"2026-08-21T03:30:39.798313606Z","published":"2026-08-10T11:58:43.727Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68123.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/100a23b1613e9218e0af654ef102352c713f0263"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2623c48cc3a8da9a1886fd8f65c0e348f4406fd6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4032f8ed10fcb84d41c508dfb04be96589f78dfe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/50a6a85f3d6b1d22d8436848606cdef5d2c490b4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e211b081901ffca76674082c73eeaed53524c369"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ea85dbcbe8d4056ecb54352f97743d138ea4c407"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68123.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68123"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1"},{"fixed":"50a6a85f3d6b1d22d8436848606cdef5d2c490b4"},{"fixed":"2623c48cc3a8da9a1886fd8f65c0e348f4406fd6"},{"fixed":"e211b081901ffca76674082c73eeaed53524c369"},{"fixed":"a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855"},{"fixed":"fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc"},{"fixed":"100a23b1613e9218e0af654ef102352c713f0263"},{"fixed":"ea85dbcbe8d4056ecb54352f97743d138ea4c407"},{"fixed":"4032f8ed10fcb84d41c508dfb04be96589f78dfe"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68123.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.8.0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68123.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}