{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23394 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23394 is a medium-severity vulnerability in Linux kernel, published on 25 Mar 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-2026-23394 and fix it if it is affected.\n\nWhat it is: CVE-2026-23394 is a medium-severity vulnerability in Linux kernel, published on 25 Mar 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-2026-23394 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-2026-23394/ (Markdown: https://insights.sbomify.com/CVE-2026-23394/index.md)","id":"CVE-2026-23394","markdown":"https://insights.sbomify.com/CVE-2026-23394/index.md","name":"CVE-2026-23394","record":{"aliases":["AZL-84053","BELL-CVE-2026-23394","DEBIAN-CVE-2026-23394","GHSA-p5pc-67g7-qcv2","ROOT-OS-DEBIAN-12-CVE-2026-23394","ROOT-OS-DEBIAN-13-CVE-2026-23394","ROOT-OS-UBUNTU-2404-CVE-2026-23394","UBUNTU-CVE-2026-23394"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in Linux kernel Unix socket garbage collection allows an attacker to cause denial of service by purging receive queues of alive sockets.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":4.7,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Give up GC if MSG_PEEK intervened.\n\nIgor Ushakov reported that GC purged the receive queue of\nan alive socket due to a race with MSG_PEEK with a nice repro.\n\nThis is the exact same issue previously fixed by commit\ncbcf01128d0a (\"af_unix: fix garbage collect vs MSG_PEEK\").\n\nAfter GC was replaced with the current algorithm, the cited\ncommit removed the locking dance in unix_peek_fds() and\nreintroduced the same issue.\n\nThe problem is that MSG_PEEK bumps a file refcount without\ninteracting with GC.\n\nConsider an SCC containing sk-A and sk-B, where sk-A is\nclose()d but can be recv()ed via sk-B.\n\nThe bad thing happens if sk-A is recv()ed with MSG_PEEK from\nsk-B and sk-B is close()d while GC is checking unix_vertex_dead()\nfor sk-A and sk-B.\n\n  GC thread                    User thread\n  ---------                    -----------\n  unix_vertex_dead(sk-A)\n  -\u003e true   \u003c------.\n                    \\\n                     `------   recv(sk-B, MSG_PEEK)\n              invalidate !!    -\u003e sk-A's file refcount : 1 -\u003e 2\n\n                               close(sk-B)\n                               -\u003e sk-B's file refcount : 2 -\u003e 1\n  unix_vertex_dead(sk-B)\n  -\u003e true\n\nInitially, sk-A's file refcount is 1 by the inflight fd in sk-B\nrecvq.  GC thinks sk-A is dead because the file refcount is the\nsame as the number of its inflight fds.\n\nHowever, sk-A's file refcount is bumped silently by MSG_PEEK,\nwhich invalidates the previous evaluation.\n\nAt this moment, sk-B's file refcount is 2; one by the open fd,\nand one by the inflight fd in sk-A.  The subsequent close()\nreleases one refcount by the former.\n\nFinally, GC incorrectly concludes that both sk-A and sk-B are dead.\n\nOne option is to restore the locking dance in unix_peek_fds(),\nbut we can resolve this more elegantly thanks to the new algorithm.\n\nThe point is that the issue does not occur without the subsequent\nclose() and we actually do not need to synchronise MSG_PEEK with\nthe dead SCC detection.\n\nWhen the issue occurs, close() and GC touch the same file refcount.\nIf GC sees the refcount being decremented by close(), it can just\ngive up garbage-collecting the SCC.\n\nTherefore, we only need to signal the race during MSG_PEEK with\na proper memory barrier to make it visible to the GC.\n\nLet's use seqcount_t to notify GC when MSG_PEEK occurs and let\nit defer the SCC to the next run.\n\nThis way no locking is needed on the MSG_PEEK side, and we can\navoid imposing a penalty on every MSG_PEEK unnecessarily.\n\nNote that we can retry within unix_scc_dead() if MSG_PEEK is\ndetected, but we do not do so to avoid hung task splat from\nabusive MSG_PEEK calls.","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":"af_unix: Give up GC if MSG_PEEK intervened.","id":"CVE-2026-23394","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":6,"next":{"headline":"Bluetooth: L2CAP: Fix accepting multiple L2CAP_ECRED_CONN_REQ","id":"CVE-2026-23395"},"packages":[],"prev":{"headline":"bridge: cfm: Fix race condition in peer_mep deletion","id":"CVE-2026-23393"},"products":["Linux"],"published":"2026-03-25","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":"2026-08-19","vendors":["Linux"]},"summary":"A race condition in Linux kernel Unix socket garbage collection allows an attacker to cause denial of service by purging receive queues of alive sockets.","url":"https://insights.sbomify.com/CVE-2026-23394/"}