{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31711 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-31711 is a high-severity denial of service vulnerability in Linux kernel, published on 1 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-31711 and fix it if it is affected.\n\nWhat it is: CVE-2026-31711 is a high-severity denial of service vulnerability in Linux kernel, published on 1 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-31711 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-2026-31711/ (Markdown: https://insights.sbomify.com/CVE-2026-31711/index.md)","id":"CVE-2026-31711","markdown":"https://insights.sbomify.com/CVE-2026-31711/index.md","name":"CVE-2026-31711","record":{"aliases":["BELL-CVE-2026-31711","DEBIAN-CVE-2026-31711","GHSA-f3m4-27m2-3p6q","ROOT-OS-DEBIAN-12-CVE-2026-31711","ROOT-OS-UBUNTU-2204-CVE-2026-31711","ROOT-OS-UBUNTU-2404-CVE-2026-31711","UBUNTU-CVE-2026-31711"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel SMB server","requires_auth":"none","summary":"An unauthenticated remote attacker can cause a denial of service in the Linux kernel SMB server by exhausting connection slots through memory allocation failures.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/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\nsmb: server: fix active_num_conn leak on transport allocation failure\n\nCommit 77ffbcac4e56 (\"smb: server: fix leak of active_num_conn in\nksmbd_tcp_new_connection()\") addressed the kthread_run() failure\npath.  The earlier alloc_transport() == NULL path in the same\nfunction has the same leak, is reachable pre-authentication via any\nTCP connect to port 445, and was empirically reproduced on UML\n(ARCH=um, v7.0-rc7): a small number of forced allocation failures\nwere sufficient to put ksmbd into a state where every subsequent\nconnection attempt was rejected for the remainder of the boot.\n\nksmbd_kthread_fn() increments active_num_conn before calling\nksmbd_tcp_new_connection() and discards the return value, so when\nalloc_transport() returns NULL the socket is released and -ENOMEM\nreturned without decrementing the counter.  Each such failure\npermanently consumes one slot from the max_connections pool; once\ncumulative failures reach the cap, atomic_inc_return() hits the\nthreshold on every subsequent accept and every new connection is\nrejected.  The counter is only reset by module reload.\n\nAn unauthenticated remote attacker can drive the server toward the\nmemory pressure that makes alloc_transport() fail by holding open\nconnections with large RFC1002 lengths up to MAX_STREAM_PROT_LEN\n(0x00FFFFFF); natural transient allocation failures on a loaded\nhost produce the same drift more slowly.\n\nMirror the existing rollback pattern in ksmbd_kthread_fn(): on the\nalloc_transport() failure path, decrement active_num_conn gated on\nserver_conf.max_connections.\n\nRepro details: with the patch reverted, forced alloc_transport()\nNULL returns leaked counter slots and subsequent connection\nattempts -- including legitimate connects issued after the\nforced-fail window had closed -- were all rejected with \"Limit the\nmaximum number of connections\".  With this patch applied, the same\nconnect sequence produces no rejections and the counter cycles\ncleanly between zero and one on every accept.","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":"smb: server: fix active_num_conn leak on transport allocation failure","id":"CVE-2026-31711","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":7,"next":{"headline":"ksmbd: require minimum ACE size in smb_check_perm_dacl()","id":"CVE-2026-31712"},"packages":[],"prev":{"headline":"smb: client: fix dir separator in SMB1 UNIX mounts","id":"CVE-2026-31710"},"products":["Linux"],"published":"2026-05-01","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)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"An unauthenticated remote attacker can cause a denial of service in the Linux kernel SMB server by exhausting connection slots through memory allocation failures.","url":"https://insights.sbomify.com/CVE-2026-31711/"}