{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-99123 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-99123 is a vulnerability in Linux, published on 28 Oct 2026."},"fix_prompt":"Check this codebase for CVE-2026-99123 and fix it if it is affected.\n\nWhat it is: CVE-2026-99123 is a vulnerability in Linux, published on 28 Oct 2026. \nExploitation: There is no known exploitation of CVE-2026-99123 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-2026-99123/ (Markdown: https://insights.sbomify.com/CVE-2026-99123/index.md)","id":"CVE-2026-99123","markdown":"https://insights.sbomify.com/CVE-2026-99123/index.md","name":"CVE-2026-99123","record":{"aliases":["AZL-111227","BELL-CVE-2026-99123","DEBIAN-CVE-2026-99123","GHSA-vf8c-hhh3-5w4x","UBUNTU-CVE-2026-99123"],"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\nvsock/virtio: validate packet source for connected sockets\n\nvirtio_transport_recv_pkt() looks up sockets first by the full source and\ndestination tuple, then by destination only in the bound table. The\nfallback is needed for listening and connecting sockets, but sockets remain\nin the bound table after connect(), so it can also return a non-listening\nsocket.\n\nThe fallback does not validate the source address. In TCP_SYN_SENT, a\nRESPONSE from an unrelated source can transition the victim socket to\nTCP_ESTABLISHED while its stored remote address remains unchanged.\nSubsequent RW packets from that source are delivered through the same\ndestination-only fallback.\n\nThis was reproduced with capability-empty processes under different UIDs.\nThe attacker discovered the target tuple through unprivileged AF_VSOCK\nsock_diag and caused the victim socket to read 16 attacker-chosen bytes;\nthe intended peer-side socket read 0 of those 16 bytes.\n\nAdd vsock_check_source() to validate the transport, source port and source\nCID against the peer stored in a non-listening socket. The local transport\nis the CID exception because its packets are generated internally with\nVMADDR_CID_LOCAL as their source, including connections using CID aliases.\n\nUse the helper after lock_sock() in the virtio receive path.","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":"vsock/virtio: validate packet source for connected sockets","id":"CVE-2026-99123","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":null,"year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"s390/pci: Fix leak of uninitialized kernel data in SCLP report","id":"CVE-2026-99124"},"packages":[],"prev":{"headline":"vsock/vmci: validate packet source for connected sockets","id":"CVE-2026-99122"},"products":["Linux"],"published":"2026-10-28","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":"2026-10-28","vendors":["Linux"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2026-99123/"}