{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-52993: tipc: fix double-free in tipc_buf_append()","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-52993","status":"final","version":"1","initial_release_date":"2026-06-24T16:29:06.475Z","current_release_date":"2026-06-28T06:37:46.811Z","revision_history":[{"date":"2026-06-24T16:29:06.475Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-52993 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-52993"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-52993"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a"}]},"product_tree":{"branches":[{"category":"vendor","name":"Linux","branches":[{"category":"product_name","name":"Linux","branches":[{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <a438975a6dcdbd70865978c021650d1485586f0b","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <a438975a6dcdbd70865978c021650d1485586f0b","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <4ee4deadaae7cb2e3d53af0fc889cf92a73413c0","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <4ee4deadaae7cb2e3d53af0fc889cf92a73413c0","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <d3556656c6daebf8def751c7e71d11dd0a180d24","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <d3556656c6daebf8def751c7e71d11dd0a180d24","product_id":"CSAFPID-3","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <0274f24485fc38032d4093e463dc3ff5c7a667c9","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <0274f24485fc38032d4093e463dc3ff5c7a667c9","product_id":"CSAFPID-4","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <4d104882bc815d4ec666ace9155f5f52715879a6","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <4d104882bc815d4ec666ace9155f5f52715879a6","product_id":"CSAFPID-5","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <1d5e589055880fae229e229e1929e087dbe08cf3","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <1d5e589055880fae229e229e1929e087dbe08cf3","product_id":"CSAFPID-6","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <29940fff14110ca48c5ccc168d121665b51bb778","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <29940fff14110ca48c5ccc168d121665b51bb778","product_id":"CSAFPID-7","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=d618d09a68e4eed7a435beb2e355250f6f40664a <d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a","product":{"name":"Linux Linux >=d618d09a68e4eed7a435beb2e355250f6f40664a <d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a","product_id":"CSAFPID-8","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}}]}]},{"category":"vendor","name":"Linux","branches":[{"category":"product_name","name":"Linux","branches":[{"category":"product_version","name":"4.15","product":{"name":"Linux Linux 4.15","product_id":"CSAFPID-9","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"0","product":{"name":"Linux Linux 0","product_id":"CSAFPID-10","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"5.10.258","product":{"name":"Linux Linux 5.10.258","product_id":"CSAFPID-11","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"5.15.209","product":{"name":"Linux Linux 5.15.209","product_id":"CSAFPID-12","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.1.175","product":{"name":"Linux Linux 6.1.175","product_id":"CSAFPID-13","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.6.141","product":{"name":"Linux Linux 6.6.141","product_id":"CSAFPID-14","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.12.91","product":{"name":"Linux Linux 6.12.91","product_id":"CSAFPID-15","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.18.33","product":{"name":"Linux Linux 6.18.33","product_id":"CSAFPID-16","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"7.0.10","product":{"name":"Linux Linux 7.0.10","product_id":"CSAFPID-17","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"7.1","product":{"name":"Linux Linux 7.1","product_id":"CSAFPID-18","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:4.15:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-52993","title":"tipc: fix double-free in tipc_buf_append()","notes":[{"category":"description","text":"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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5","CSAFPID-6","CSAFPID-7","CSAFPID-8","CSAFPID-9"],"fixed":["CSAFPID-10","CSAFPID-11","CSAFPID-12","CSAFPID-13","CSAFPID-14","CSAFPID-15","CSAFPID-16","CSAFPID-17","CSAFPID-18"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5","CSAFPID-6","CSAFPID-7","CSAFPID-8","CSAFPID-9"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 0, 0274f24485fc38032d4093e463dc3ff5c7a667c9, 1d5e589055880fae229e229e1929e087dbe08cf3, 29940fff14110ca48c5ccc168d121665b51bb778, 4d104882bc815d4ec666ace9155f5f52715879a6, 4ee4deadaae7cb2e3d53af0fc889cf92a73413c0, 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1, a438975a6dcdbd70865978c021650d1485586f0b, d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a, d3556656c6daebf8def751c7e71d11dd0a180d24.","product_ids":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5","CSAFPID-6","CSAFPID-7","CSAFPID-8","CSAFPID-9"]}]}]}