{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98595 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98595 is a denial of service vulnerability in Linux, published on 18 Oct 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-2026-98595 and fix it if it is affected.\n\nWhat it is: CVE-2026-98595 is a denial of service vulnerability in Linux, published on 18 Oct 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-2026-98595 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-2026-98595/ (Markdown: https://insights.sbomify.com/CVE-2026-98595/index.md)","id":"CVE-2026-98595","markdown":"https://insights.sbomify.com/CVE-2026-98595/index.md","name":"CVE-2026-98595","record":{"aliases":["BELL-CVE-2026-98595","DEBIAN-CVE-2026-98595","GHSA-mg64-mpw7-gmp2","UBUNTU-CVE-2026-98595"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A Linux kernel UDP socket handling flaw allows remote attackers to cause denial of service by forcing inefficient packet processing through stale hash table entries.","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\nudp: remove a disconnected socket from the 4-tuple hash table\n\nA UDP socket bound to a specific address and port keeps its entry in the\n4-tuple hash table after it is disconnected:\n\n    sk binds to 127.0.0.1:21001\n    sk connects to 127.0.0.2:20001\t// filed in the 4-tuple table\n    sk disconnects, connect(AF_UNSPEC)\t// still filed, peer now 0.0.0.0:0\n\n__udp_disconnect() takes a socket out of that table only as a side effect\nof -\u003erehash() or -\u003eunhash(), and it skips -\u003erehash() when\nSOCK_BINDADDR_LOCK is set and -\u003eunhash() when SOCK_BINDPORT_LOCK is set.\ncommit 6996a2d2d0a6 (\"udp: Unhash auto-bound connected sk from 4-tuple hash\ntable when disconnected.\") fixed the same end state for a wildcard-bound\nsocket, by a path this one does not take.\n\nThe entry is counted whether or not anything hits it. hash4_cnt on the\nhash2 slot stays raised for as long as the socket lives, so udp_has_hash4()\nkeeps sending every packet for that address and port through the 4-tuple\nlookup first.\n\nOn IPv6 it can also be hit. __udp_disconnect() does not clear sk_v6_daddr,\nso udp_v6_rehash() files the entry under the peer the socket was connected\nto with a zero dport, and inet6_match() compares that same\nfield: a datagram from the former peer with a zero source port matches,\nand source port zero is accepted on receive. On IPv4 the peer is cleared,\nso a match would need a zero source address as well, which the routing\nlayer rejects as martian. The stale sk_v6_daddr is a separate defect, not\naddressed here; removing the entry closes this path either way.\n\nThe entry can also be relocated. __udp_disconnect() clears sk_bound_dev_if,\nso a subsequent SO_BINDTODEVICE calls -\u003erehash(), and because the receive\naddress is still specific udp_lib_rehash() moves the entry instead of\nremoving it, into the bucket that (rcv_saddr, num, 0, 0) hashes to -- a\npure function of the address and port, so every socket reaching this state\non one address and port collects in one bucket. The bucket cannot be chosen\nfrom outside, as udp_ehashfn() is seeded with a per-boot secret. This last\none became reachable only with commit 644f9108f3a5 (\"udp: Make rehash4\nindependent in udp_lib_rehash()\"), which moved the hash4 handling out of a\nbranch a disconnected socket does not take; the stale entry itself dates\nfrom the commit in Fixes.\n\nTake the socket out of the table before __udp_disconnect() runs, while it\nstill matches how it was filed. This also reaches the wildcard case ahead\nof udp_lib_rehash()'s udp_unhash4() branch, leaving that branch unreachable\nfrom udp_disconnect(); removing it belongs in net-next. udp_disconnect()\nand udp_abort() are the only UDP entries into __udp_disconnect(), which is\nshared with raw, ping and l2tp sockets that are not struct udp_sock:\nping_prot.obj_size is sizeof(struct inet_sock), so udp_hashed4() on one\nwould read past the allocation.","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":"udp: remove a disconnected socket from the 4-tuple hash table","id":"CVE-2026-98595","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"ipv6: Fix dst leak for uncached routes.","id":"CVE-2026-98596"},"packages":[],"prev":{"headline":"tg3: clean up PHYLIB resources on probe failure","id":"CVE-2026-98594"},"products":["Linux"],"published":"2026-10-18","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":"2026-10-19","vendors":["Linux"]},"summary":"A Linux kernel UDP socket handling flaw allows remote attackers to cause denial of service by forcing inefficient packet processing through stale hash table entries.","url":"https://insights.sbomify.com/CVE-2026-98595/"}