{"id":"CVE-2026-52993","summary":"tipc: fix double-free in tipc_buf_append()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix double-free in tipc_buf_append()\n\ntipc_msg_validate() can potentially reallocate the skb it is validating,\nfreeing the old one.  In tipc_buf_append(), it was being called with a\npointer to a local variable which was a copy of the caller's skb\npointer.\n\nIf the skb was reallocated and validation subsequently failed, the error\nhandling path would free the original skb pointer, which had already\nbeen freed, leading to double-free.\n\nFix this by checking if head now points to a newly allocated reassembled\nskb.  If it does, reassign *headbuf for later freeing operations.","modified":"2026-07-12T03:55:06.792326599Z","published":"2026-06-24T16:29:06.475Z","related":["SUSE-SU-2026:2840-1","SUSE-SU-2026:2841-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52993.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.json"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-52993"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52993.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52993"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492437"},{"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":"d618d09a68e4eed7a435beb2e355250f6f40664a"},{"fixed":"a438975a6dcdbd70865978c021650d1485586f0b"},{"fixed":"4ee4deadaae7cb2e3d53af0fc889cf92a73413c0"},{"fixed":"d3556656c6daebf8def751c7e71d11dd0a180d24"},{"fixed":"0274f24485fc38032d4093e463dc3ff5c7a667c9"},{"fixed":"4d104882bc815d4ec666ace9155f5f52715879a6"},{"fixed":"1d5e589055880fae229e229e1929e087dbe08cf3"},{"fixed":"29940fff14110ca48c5ccc168d121665b51bb778"},{"fixed":"d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52993.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"5.10.258"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.209"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.141"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52993.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}