{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-52943 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-52943 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-52943 and fix it if it is affected.\n\nWhat it is: CVE-2026-52943 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-52943 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-52943/ (Markdown: https://insights.sbomify.com/CVE-2026-52943/index.md)","id":"CVE-2026-52943","markdown":"https://insights.sbomify.com/CVE-2026-52943/index.md","name":"CVE-2026-52943","record":{"aliases":["AZL-90308","BELL-CVE-2026-52943","DEBIAN-CVE-2026-52943","GHSA-vwrr-994w-h832","ROOT-OS-DEBIAN-11-CVE-2026-52943","ROOT-OS-DEBIAN-12-CVE-2026-52943","ROOT-OS-UBUNTU-2204-CVE-2026-52943","ROOT-OS-UBUNTU-2404-CVE-2026-52943","UBUNTU-CVE-2026-52943"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["privilege_escalation","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A use-after-free in the Linux kernel network stack allows local attackers to achieve root privilege escalation via crafted network packets.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-911","name":"Improper Update of Reference Count"},{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skbuff: fix missing zerocopy reference in pskb_carve helpers\n\npskb_carve_inside_header() and pskb_carve_inside_nonlinear() both copy\nthe old skb_shared_info header into a new buffer via memcpy(), which\nincludes the destructor_arg pointer (uarg) for MSG_ZEROCOPY skbs.\nNeither function calls net_zcopy_get() for the new shinfo, creating an\nunaccounted holder: every skb_shared_info with destructor_arg set will\ncall skb_zcopy_clear() once when freed, but the corresponding\nnet_zcopy_get() was never called for the new copy. Repeated calls\ndrive uarg-\u003erefcnt to zero prematurely, freeing ubuf_info_msgzc while\nTX skbs still hold live destructor_arg pointers.\n\nKASAN reports use-after-free on a freed ubuf_info_msgzc:\n\n  BUG: KASAN: slab-use-after-free in skb_release_data+0x77b/0x810\n  Read of size 8 at addr ffff88801574d3e8 by task poc/220\n\n  Call Trace:\n   skb_release_data+0x77b/0x810\n   kfree_skb_list_reason+0x13e/0x610\n   skb_release_data+0x4cd/0x810\n   sk_skb_reason_drop+0xf3/0x340\n   skb_queue_purge_reason+0x282/0x440\n   rds_tcp_inc_free+0x1e/0x30\n   rds_recvmsg+0x354/0x1780\n   __sys_recvmsg+0xdf/0x180\n\n  Allocated by task 219:\n   msg_zerocopy_realloc+0x157/0x7b0\n   tcp_sendmsg_locked+0x2892/0x3ba0\n\n  Freed by task 219:\n   ip_recv_error+0x74a/0xb10\n   tcp_recvmsg+0x475/0x530\n\nThe skb consuming the late access still referenced the same uarg via\nshinfo-\u003edestructor_arg copied by pskb_carve_inside_nonlinear() without\na refcount bump. This has been verified to be reliably exploitable: a\nworking proof-of-concept achieves full root privilege escalation from\nan unprivileged local user on a default kernel configuration.\n\nThe fix follows the pattern of pskb_expand_head() which has the same\nmemcpy/cloned structure. For pskb_carve_inside_header(), net_zcopy_get()\nis placed after skb_orphan_frags() succeeds, so the orphan error path\nneeds no cleanup. For pskb_carve_inside_nonlinear(), net_zcopy_get() is\nplaced after all failure points and just before skb_release_data(), so\nno error path needs cleanup at all -- matching pskb_expand_head() more\nclosely and avoiding the need for a balancing net_zcopy_put().","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-06-16","github_poc":1,"max_poc_stars":9,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-06-16T10:16:55Z","kind":"github_poc","ref":"https://github.com/vn-lazyming/CVE-2026-52943","stars":9,"title":"This is a Linux Kernel Local Privilege Escalation PoC code for CVE-2026-52943 a use-after-free in skbuff.c, my first 0day found by me in linux kernel"}],"tier":"poc_unverified"},"has_fix":true,"headline":"net: skbuff: fix missing zerocopy reference in pskb_carve helpers","id":"CVE-2026-52943","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTL_SET_SPARSE","id":"CVE-2026-52944"},"packages":[],"prev":{"headline":"netfilter: nf_log: validate MAC header was set before dumping it","id":"CVE-2026-52942"},"products":["Linux"],"published":"2026-06-24","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A use-after-free in the Linux kernel network stack allows local attackers to achieve root privilege escalation via crafted network packets.","url":"https://insights.sbomify.com/CVE-2026-52943/"}