{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31429 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-31429 is a medium-severity memory corruption vulnerability in Linux kernel, published on 20 Apr 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-2026-31429 and fix it if it is affected.\n\nWhat it is: CVE-2026-31429 is a medium-severity memory corruption vulnerability in Linux kernel, published on 20 Apr 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-2026-31429 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-2026-31429/ (Markdown: https://insights.sbomify.com/CVE-2026-31429/index.md)","id":"CVE-2026-31429","markdown":"https://insights.sbomify.com/CVE-2026-31429/index.md","name":"CVE-2026-31429","record":{"aliases":["BELL-CVE-2026-31429","DEBIAN-CVE-2026-31429","GHSA-vqjc-m5xh-jhx3","ROOT-OS-DEBIAN-13-CVE-2026-31429","ROOT-OS-UBUNTU-2404-CVE-2026-31429","UBUNTU-CVE-2026-31429"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A Linux kernel bug allows cross-cache memory corruption when KFENCE is enabled, potentially leading to system crashes or arbitrary code execution.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-401","name":"Missing Release of Memory after Effective Lifetime"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skb: fix cross-cache free of KFENCE-allocated skb head\n\nSKB_SMALL_HEAD_CACHE_SIZE is intentionally set to a non-power-of-2\nvalue (e.g. 704 on x86_64) to avoid collisions with generic kmalloc\nbucket sizes. This ensures that skb_kfree_head() can reliably use\nskb_end_offset to distinguish skb heads allocated from\nskb_small_head_cache vs. generic kmalloc caches.\n\nHowever, when KFENCE is enabled, kfence_ksize() returns the exact\nrequested allocation size instead of the slab bucket size. If a caller\n(e.g. bpf_test_init) allocates skb head data via kzalloc() and the\nrequested size happens to equal SKB_SMALL_HEAD_CACHE_SIZE, then\nslab_build_skb() -\u003e ksize() returns that exact value. After subtracting\nskb_shared_info overhead, skb_end_offset ends up matching\nSKB_SMALL_HEAD_HEADROOM, causing skb_kfree_head() to incorrectly free\nthe object to skb_small_head_cache instead of back to the original\nkmalloc cache, resulting in a slab cross-cache free:\n\n  kmem_cache_free(skbuff_small_head): Wrong slab cache. Expected\n  skbuff_small_head but got kmalloc-1k\n\nFix this by always calling kfree(head) in skb_kfree_head(). This keeps\nthe free path generic and avoids allocator-specific misclassification\nfor KFENCE objects.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-04-24","github_poc":1,"max_poc_stars":1,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-04-24T06:30:29Z","kind":"github_poc","ref":"https://github.com/bluedragonsecurity/CVE-2026-31429-POC","stars":1,"title":"POC for CVE-2026-31429 (Linux Kernel \u003e= 6.3 \u003c 6.12.82 Slab Cross-Cache Confusion) - vulnerability discovered by Antonius - w1sdom - bluedragonsec.com"}],"tier":"poc_unverified"},"has_fix":true,"headline":"net: skb: fix cross-cache free of KFENCE-allocated skb head","id":"CVE-2026-31429","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":5,"next":{"headline":"X.509: Fix out-of-bounds access when parsing extensions","id":"CVE-2026-31430"},"packages":[],"prev":{"headline":"netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD","id":"CVE-2026-31428"},"products":["Linux"],"published":"2026-04-20","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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A Linux kernel bug allows cross-cache memory corruption when KFENCE is enabled, potentially leading to system crashes or arbitrary code execution.","url":"https://insights.sbomify.com/CVE-2026-31429/"}