{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98983 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-98983 is a vulnerability in Linux, published on 23 Oct 2026."},"fix_prompt":"Check this codebase for CVE-2026-98983 and fix it if it is affected.\n\nWhat it is: CVE-2026-98983 is a vulnerability in Linux, published on 23 Oct 2026. \nExploitation: There is no known exploitation of CVE-2026-98983 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-2026-98983/ (Markdown: https://insights.sbomify.com/CVE-2026-98983/index.md)","id":"CVE-2026-98983","markdown":"https://insights.sbomify.com/CVE-2026-98983/index.md","name":"CVE-2026-98983","record":{"aliases":["BELL-CVE-2026-98983","DEBIAN-CVE-2026-98983","GHSA-vc4v-q632-x9g5","UBUNTU-CVE-2026-98983"],"analysis":null,"analysis_generated_by":null,"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\nunshare: don't drop active namespace references that were never taken\n\nActive references on the namespaces of an nsproxy are taken when the\nnsproxy is installed into a task in switch_task_namespaces() and\ncopy_namespaces() and dropped again by put_nsproxy() through\ndeactivate_nsproxy().\n\nBut ksys_unshare() calls put_nsproxy() on an nsproxy that was never\ninstalled when set_cred_ucounts() fails. The new namespaces of that\nnsproxy go from zero to minus one and the namespaces shared with the\ncaller lose a reference that belongs to the nsproxy the caller keeps\nusing:\n\n  WARNING: kernel/nscommon.c:171 at __ns_ref_active_put+0x1cd/0x230\n   nsproxy_ns_active_put\n   deactivate_nsproxy\n   ksys_unshare\n\nAfterwards the namespaces the caller lives in aren't listed by listns()\nanymore. set_cred_ucounts() only fails when alloc_ucounts() can't\nallocate and it only allocates when the real uid of the caller differs\nfrom its effective uid.\n\nCommit cefd55bd2159 (\"nsproxy: fix free_nsproxy() and simplify\ncreate_new_namespaces()\") separated the two cases on purpose.\nnsproxy_free() frees an nsproxy that was prepared but never installed\nand that's what a failed setns() uses in put_nsset(). Export it and use\nit for a failed unshare() as well.","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":"unshare: don't drop active namespace references that were never taken","id":"CVE-2026-98983","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":null,"year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"dcache: don't put a mountpoint on a dentry that's being removed","id":"CVE-2026-98984"},"packages":[],"prev":{"headline":"namespace: don't let a pseudo dentry become the root of a mount","id":"CVE-2026-98982"},"products":["Linux"],"published":"2026-10-23","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":"2026-10-23","vendors":["Linux"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2026-98983/"}