{"id":"CVE-2026-52993","title":"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","summary":"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 …","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-763"],"published":"2026-06-24","updated":"2026-07-10","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-52993","references":[{"url":"https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://access.redhat.com/security/cve/CVE-2026-52993","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492437","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-52993"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52993"},{"url":"https://lore.kernel.org/linux-cve-announce/2026062445-CVE-2026-52993-34a2@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:47017"},{"url":"https://access.redhat.com/errata/RHSA-2026:49212"},{"url":"https://access.redhat.com/errata/RHSA-2026:45115"},{"url":"https://access.redhat.com/errata/RHSA-2026:69837"},{"url":"https://access.redhat.com/errata/RHSA-2026:45116"},{"url":"https://access.redhat.com/errata/RHSA-2026:70482"},{"url":"https://access.redhat.com/errata/RHSA-2026:69874"},{"url":"https://access.redhat.com/errata/RHSA-2026:69906"},{"url":"https://access.redhat.com/errata/RHSA-2026:70483"}],"tags":["nvd","csaf","vex","red-hat","score-dispute"],"epss":0.00368,"epssPercentile":0.30616,"ingestedAt":"2026-07-11T13:13:25.646Z","vendor":"Red Hat","product":"Red Hat Enterprise Linux BaseOS (v. 10)","affected":["enterprise_linux 9","enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_baseos_e4s_v_8_8","enterprise_linux_baseos_tus_v_8_8","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_10","enterprise_linux_crb_v_8","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_v_10","enterprise_linux_nfv_v_8","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_10","enterprise_linux_rt_v_8","enterprise_linux_real_time_v_9"],"patched":["enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_baseos_e4s_v_8_8","enterprise_linux_baseos_tus_v_8_8","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_10","enterprise_linux_crb_v_8","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_v_10","enterprise_linux_nfv_v_8","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_10","enterprise_linux_rt_v_8","enterprise_linux_real_time_v_9"],"scores":{"nvd":9.8,"vendor":7},"slug":"CVE-2026-52993","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:47017** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2026-07-28 · [advisory](https://access.redhat.com/errata/RHSA-2026:47017)\n- **RHSA-2026:49212** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-07-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:49212)\n- **RHSA-2026:45115** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-07-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:45115)\n- **RHSA-2026:69837** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS E4S (v.8.8), Red Hat Enterprise Linux BaseOS TUS (v.8.8) · released 2026-09-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:69837)\n- **RHSA-2026:45116** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-07-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:45116)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.json)\n- **RHSA-2026:70482** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2) · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70482)\n- **RHSA-2026:69874** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS AUS (v.8.4), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) · released 2026-09-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:69874)\n- **RHSA-2026:69906** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS AUS (v.8.6), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) · released 2026-09-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:69906)\n- **RHSA-2026:70483** · Red Hat · fixed in: Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2), Red Hat Enterprise Linux Real Time E4S (v.9.2) · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70483)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}