{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23111 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23111 is a high-severity use after free vulnerability in Linux kernel, published on 13 Feb 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-2026-23111 and fix it if it is affected.\n\nWhat it is: CVE-2026-23111 is a high-severity use after free vulnerability in Linux kernel, published on 13 Feb 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-2026-23111 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-2026-23111/ (Markdown: https://insights.sbomify.com/CVE-2026-23111/index.md)","id":"CVE-2026-23111","markdown":"https://insights.sbomify.com/CVE-2026-23111/index.md","name":"CVE-2026-23111","record":{"aliases":["AZL-77483","BELL-CVE-2026-23111","DEBIAN-CVE-2026-23111","GHSA-jh9m-9mr6-3ghc","ROOT-OS-DEBIAN-11-CVE-2026-23111","ROOT-OS-DEBIAN-12-CVE-2026-23111","ROOT-OS-DEBIAN-13-CVE-2026-23111","ROOT-OS-UBUNTU-2204-CVE-2026-23111","ROOT-OS-UBUNTU-2404-CVE-2026-23111","UBUNTU-CVE-2026-23111","USN-8148-1","USN-8148-2","USN-8148-3","USN-8148-4","USN-8149-3"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"Local attackers can exploit a use-after-free in Linux kernel nftables to achieve privilege escalation via user namespaces.","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-672","name":"Operation on a Resource after Expiration or Release"},{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: fix inverted genmask check in nft_map_catchall_activate()\n\nnft_map_catchall_activate() has an inverted element activity check\ncompared to its non-catchall counterpart nft_mapelem_activate() and\ncompared to what is logically required.\n\nnft_map_catchall_activate() is called from the abort path to re-activate\ncatchall map elements that were deactivated during a failed transaction.\nIt should skip elements that are already active (they don't need\nre-activation) and process elements that are inactive (they need to be\nrestored). Instead, the current code does the opposite: it skips inactive\nelements and processes active ones.\n\nCompare the non-catchall activate callback, which is correct:\n\n  nft_mapelem_activate():\n    if (nft_set_elem_active(ext, iter-\u003egenmask))\n        return 0;   /* skip active, process inactive */\n\nWith the buggy catchall version:\n\n  nft_map_catchall_activate():\n    if (!nft_set_elem_active(ext, genmask))\n        continue;   /* skip inactive, process active */\n\nThe consequence is that when a DELSET operation is aborted,\nnft_setelem_data_activate() is never called for the catchall element.\nFor NFT_GOTO verdict elements, this means nft_data_hold() is never\ncalled to restore the chain-\u003euse reference count. Each abort cycle\npermanently decrements chain-\u003euse. Once chain-\u003euse reaches zero,\nDELCHAIN succeeds and frees the chain while catchall verdict elements\nstill reference it, resulting in a use-after-free.\n\nThis is exploitable for local privilege escalation from an unprivileged\nuser via user namespaces + nftables on distributions that enable\nCONFIG_USER_NS and CONFIG_NF_TABLES.\n\nFix by removing the negation so the check matches nft_mapelem_activate():\nskip active elements, process inactive ones.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-06-09","github_poc":10,"max_poc_stars":10,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-08-12T13:23:42Z","kind":"github_poc","ref":"https://github.com/Knz-source/CVE-2026-23111-POC-noddlenpottato","stars":10,"title":"CVE-2026-23111 nf_tables catchall UAF — unprivileged LPE for Linux 5.10-6.18. Auto-adaptive exploit with KASLR bypass, arbitrary kernel read, and ROP chain. Supports Debian, Ubuntu, RHEL, Fedora. C/Python/Rust + autopwn."},{"date":"2026-06-25T11:15:38Z","kind":"github_poc","ref":"https://github.com/Baba01hacker666/CVE-2026-23111","stars":7,"title":"Linux Kernel nf_tables Use-After-Free (CVE-2026-23111) — LPE PoC"},{"date":"2026-06-09T10:46:06Z","kind":"github_poc","ref":"https://github.com/0xredash/CVE-2026-23111","stars":5,"title":"CVE-2026-23111"},{"date":"2026-10-19T08:41:50Z","kind":"github_poc","ref":"https://github.com/kinokopio/CVE-2026-23111","stars":5,"title":"CVE-2026-23111 nf_tables UAF exploit for Ubuntu 6.8.0-101-generic: unprivileged user → host root, plus container escape to the host."},{"date":"2026-06-11T16:28:31Z","kind":"github_poc","ref":"https://github.com/ishankaru/CVE-2026-23111-nftables-lab","stars":2,"title":"Exposure checker and safe disposable-VM lab for CVE-2026-23111 (Linux nf_tables use-after-free local privilege escalation). Defensive: detection, mitigation, multi-distro lab. No exploit."},{"date":"2026-07-01T13:21:55Z","kind":"github_poc","ref":"https://github.com/bakano98/cve-2026-23111-poc","stars":1,"title":"scuffed PoC for CVE-2026-23111. Made and ran on Linux Kernel 6.12.69"},{"date":"2026-06-09T01:25:18Z","kind":"github_poc","ref":"https://github.com/HORKimhab/CVE-2026-23111","stars":0,"title":"CVE-2026-23111 - Linux - Draft"},{"date":"2026-06-09T10:28:09Z","kind":"github_poc","ref":"https://github.com/criann/check-cve-2026-23111","stars":0,"title":"Script to check if system are vulnable to cve-2026-23111"}],"tier":"poc_unverified"},"has_fix":true,"headline":"netfilter: nf_tables: fix inverted genmask check in nft_map_catchall_activate()","id":"CVE-2026-23111","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":6,"next":{"headline":"nvmet-tcp: add bounds checks in nvmet_tcp_build_pdu_iovec","id":"CVE-2026-23112"},"packages":[],"prev":{"headline":"scsi: core: Wake up the error handler when final completions race against each other","id":"CVE-2026-23110"},"products":["Linux"],"published":"2026-02-13","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":"2026-10-15","vendors":["Linux"]},"summary":"Local attackers can exploit a use-after-free in Linux kernel nftables to achieve privilege escalation via user namespaces.","url":"https://insights.sbomify.com/CVE-2026-23111/"}