{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-90099 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-90099 is a denial of service vulnerability in Linux, published on 17 Sep 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-2026-90099 and fix it if it is affected.\n\nWhat it is: CVE-2026-90099 is a denial of service vulnerability in Linux, published on 17 Sep 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-2026-90099 in the wild and no public exploit code.\n\nAffected product: Linux. 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-2026-90099/ (Markdown: https://insights.sbomify.com/CVE-2026-90099/index.md)","id":"CVE-2026-90099","markdown":"https://insights.sbomify.com/CVE-2026-90099/index.md","name":"CVE-2026-90099","record":{"aliases":["AZL-102560","BELL-CVE-2026-90099","DEBIAN-CVE-2026-90099","GHSA-3537-p4vp-g252","UBUNTU-CVE-2026-90099"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"Unprivileged users can exhaust kernel memory via tc classifier filters, causing denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: account classifier filter allocations to memcg\n\nAllocations in the tc classifier *_change() paths (filter objects,\nper-CPU counters, and per-filter aux data) use plain GFP_KERNEL without\n__GFP_ACCOUNT, allowing unprivileged users to pin kernel memory outside\nmemcg charging. The shared tcf_exts_init_ex() action array allocation in\ncls_api.c was also uncharged; this patch closes it along with the\nper-classifier filter-object/percpu/aux allocations that remain\nunaccounted.\n\nAdd GFP_KERNEL_ACCOUNT to:\n- the shared tcf_exts_init_ex() action array (cls_api.c), common to every\n  filter of every classifier (32 pointers, 256 bytes);\n- the filter-object, per-CPU-counter, and per-filter aux allocations in\n  cls_basic, cls_bpf, cls_cgroup, cls_flow, cls_flower, cls_fw,\n  cls_matchall, cls_route and cls_u32;\n- the u32_init_knode() replace-path knode allocation (cls_u32.c), which\n  allocates the same struct tc_u_knode + sel.keys on every replace of an\n  existing knode and was missed by the create-path-only conversion.\n\nAlso fix the cls_basic error path: basic_change() inserts fnew into the\nIDR before allocating the per-CPU counter. If alloc_percpu() fails the\nerrout path kfree'd fnew without idr_remove, leaving a dangling pointer\nin the IDR. With GFP_KERNEL_ACCOUNT the percpu alloc becomes failable\non demand (memcg at memory.max), making the dead path attacker-reachable\nand burning the handle permanently. Add the idr_remove on the percpu\nfailure path, matching the basic_set_parms failure-path pattern.\n\nNote: vega@nebusec.ai provided a poc for basic_cls, but it was easy to\nextend to the other classifiers.\n\nConditions to recreate the bug:\n- CONFIG_NET_SCHED, CONFIG_NET_CLS_* (the classifier being used),\n  CONFIG_NET_CLS_ACT, CONFIG_MEMCG, CONFIG_USER_NS, CONFIG_NET_NS.\n- Unprivileged user in a fresh user+network namespace (unshare -Urn),\n  or root with CAP_NET_ADMIN.\n- Create a large number of tc filters (e.g. tc filter add dev lo\n  ingress ... \u003cclassifier\u003e ...) while watching a memcg-limited cgroup:\n  system slab grows far faster than memory.current, pinning kernel\n  memory outside memcg charging.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"net/sched: account classifier filter allocations to memcg","id":"CVE-2026-90099","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":5,"next":{"headline":"ptp: netc: fix period truncation and potential divide-by-zero in PEROUT","id":"CVE-2026-90100"},"packages":[],"prev":{"headline":"net: sparx5: fix sleep in atomic context in MAC table access","id":"CVE-2026-90098"},"products":["Linux"],"published":"2026-09-17","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-21","vendors":["Linux"]},"summary":"Unprivileged users can exhaust kernel memory via tc classifier filters, causing denial of service.","url":"https://insights.sbomify.com/CVE-2026-90099/"}