{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23276 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23276 is a medium-severity denial of service vulnerability in Linux kernel, published on 20 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-2026-23276 and fix it if it is affected.\n\nWhat it is: CVE-2026-23276 is a medium-severity denial of service vulnerability in Linux kernel, published on 20 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-2026-23276 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-2026-23276/ (Markdown: https://insights.sbomify.com/CVE-2026-23276/index.md)","id":"CVE-2026-23276","markdown":"https://insights.sbomify.com/CVE-2026-23276/index.md","name":"CVE-2026-23276","record":{"aliases":["AZL-80216","BELL-CVE-2026-23276","DEBIAN-CVE-2026-23276","GHSA-89g4-663g-prjh","ROOT-OS-DEBIAN-11-CVE-2026-23276","ROOT-OS-DEBIAN-12-CVE-2026-23276","ROOT-OS-DEBIAN-13-CVE-2026-23276","ROOT-OS-UBUNTU-2204-CVE-2026-23276","ROOT-OS-UBUNTU-2404-CVE-2026-23276","UBUNTU-CVE-2026-23276"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel networking","requires_auth":"low_privilege","summary":"A missing recursion limit in Linux kernel tunnel transmission functions allows attackers to cause a kernel stack overflow and system crash via specific network configurations.","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":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-674","name":"Uncontrolled Recursion"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: add xmit recursion limit to tunnel xmit functions\n\nTunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own\nrecursion limit. When a bond device in broadcast mode has GRE tap\ninterfaces as slaves, and those GRE tunnels route back through the\nbond, multicast/broadcast traffic triggers infinite recursion between\nbond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing\nkernel stack overflow.\n\nThe existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not\nsufficient because tunnel recursion involves route lookups and full IP\noutput, consuming much more stack per level. Use a lower limit of 4\n(IP_TUNNEL_RECURSION_LIMIT) to prevent overflow.\n\nAdd recursion detection using dev_xmit_recursion helpers directly in\niptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel\npaths including UDP encapsulated tunnels (VXLAN, Geneve, etc.).\n\nMove dev_xmit_recursion helpers from net/core/dev.h to public header\ninclude/linux/netdevice.h so they can be used by tunnel code.\n\n BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160\n Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11\n Workqueue: mld mld_ifc_work\n Call Trace:\n  \u003cTASK\u003e\n  __build_flow_key.constprop.0 (net/ipv4/route.c:515)\n  ip_rt_update_pmtu (net/ipv4/route.c:1073)\n  iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84)\n  ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n  gre_tap_xmit (net/ipv4/ip_gre.c:779)\n  dev_hard_start_xmit (net/core/dev.c:3887)\n  sch_direct_xmit (net/sched/sch_generic.c:347)\n  __dev_queue_xmit (net/core/dev.c:4802)\n  bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n  bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n  bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n  dev_hard_start_xmit (net/core/dev.c:3887)\n  __dev_queue_xmit (net/core/dev.c:4841)\n  ip_finish_output2 (net/ipv4/ip_output.c:237)\n  ip_output (net/ipv4/ip_output.c:438)\n  iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n  gre_tap_xmit (net/ipv4/ip_gre.c:779)\n  dev_hard_start_xmit (net/core/dev.c:3887)\n  sch_direct_xmit (net/sched/sch_generic.c:347)\n  __dev_queue_xmit (net/core/dev.c:4802)\n  bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n  bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n  bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n  dev_hard_start_xmit (net/core/dev.c:3887)\n  __dev_queue_xmit (net/core/dev.c:4841)\n  ip_finish_output2 (net/ipv4/ip_output.c:237)\n  ip_output (net/ipv4/ip_output.c:438)\n  iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)\n  ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n  gre_tap_xmit (net/ipv4/ip_gre.c:779)\n  dev_hard_start_xmit (net/core/dev.c:3887)\n  sch_direct_xmit (net/sched/sch_generic.c:347)\n  __dev_queue_xmit (net/core/dev.c:4802)\n  bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)\n  bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)\n  bond_start_xmit (drivers/net/bonding/bond_main.c:5530)\n  dev_hard_start_xmit (net/core/dev.c:3887)\n  __dev_queue_xmit (net/core/dev.c:4841)\n  mld_sendpack\n  mld_ifc_work\n  process_one_work\n  worker_thread\n  \u003c/TASK\u003e","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":"net: add xmit recursion limit to tunnel xmit functions","id":"CVE-2026-23276","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":5,"next":{"headline":"net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit","id":"CVE-2026-23277"},"packages":[],"prev":{"headline":"io_uring: ensure ctx-\u003erings is stable for task work flags manipulation","id":"CVE-2026-23275"},"products":["Linux"],"published":"2026-03-20","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":"2026-10-21","vendors":["Linux"]},"summary":"A missing recursion limit in Linux kernel tunnel transmission functions allows attackers to cause a kernel stack overflow and system crash via specific network configurations.","url":"https://insights.sbomify.com/CVE-2026-23276/"}