{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23277 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23277 is a medium-severity 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-2026-23277 and fix it if it is affected.\n\nWhat it is: CVE-2026-23277 is a medium-severity 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-2026-23277 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-2026-23277/ (Markdown: https://insights.sbomify.com/CVE-2026-23277/index.md)","id":"CVE-2026-23277","markdown":"https://insights.sbomify.com/CVE-2026-23277/index.md","name":"CVE-2026-23277","record":{"aliases":["AZL-80204","BELL-CVE-2026-23277","DEBIAN-CVE-2026-23277","GHSA-v66f-jqgm-8687","ROOT-OS-DEBIAN-11-CVE-2026-23277","ROOT-OS-DEBIAN-12-CVE-2026-23277","ROOT-OS-DEBIAN-13-CVE-2026-23277","ROOT-OS-UBUNTU-2204-CVE-2026-23277","ROOT-OS-UBUNTU-2404-CVE-2026-23277","UBUNTU-CVE-2026-23277"],"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 NULL pointer dereference in the Linux kernel TEQL scheduler causes a system crash when transmitting through gretap tunnels.","user_interaction":"not_required","vuln_class":"null_dereference"},"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-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit\n\nteql_master_xmit() calls netdev_start_xmit(skb, slave) to transmit\nthrough slave devices, but does not update skb-\u003edev to the slave device\nbeforehand.\n\nWhen a gretap tunnel is a TEQL slave, the transmit path reaches\niptunnel_xmit() which saves dev = skb-\u003edev (still pointing to teql0\nmaster) and later calls iptunnel_xmit_stats(dev, pkt_len). This\nfunction does:\n\n    get_cpu_ptr(dev-\u003etstats)\n\nSince teql_master_setup() does not set dev-\u003epcpu_stat_type to\nNETDEV_PCPU_STAT_TSTATS, the core network stack never allocates tstats\nfor teql0, so dev-\u003etstats is NULL. get_cpu_ptr(NULL) computes\nNULL + __per_cpu_offset[cpu], resulting in a page fault.\n\n BUG: unable to handle page fault for address: ffff8880e6659018\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x0002) - not-present page\n PGD 68bc067 P4D 68bc067 PUD 0\n Oops: Oops: 0002 [#1] SMP KASAN PTI\n RIP: 0010:iptunnel_xmit (./include/net/ip_tunnels.h:664 net/ipv4/ip_tunnel_core.c:89)\n Call Trace:\n  \u003cTASK\u003e\n  ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n  __gre_xmit (net/ipv4/ip_gre.c:478)\n  gre_tap_xmit (net/ipv4/ip_gre.c:779)\n  teql_master_xmit (net/sched/sch_teql.c:319)\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  neigh_direct_output (net/core/neighbour.c:1660)\n  ip_finish_output2 (net/ipv4/ip_output.c:237)\n  __ip_finish_output.part.0 (net/ipv4/ip_output.c:315)\n  ip_mc_output (net/ipv4/ip_output.c:369)\n  ip_send_skb (net/ipv4/ip_output.c:1508)\n  udp_send_skb (net/ipv4/udp.c:1195)\n  udp_sendmsg (net/ipv4/udp.c:1485)\n  inet_sendmsg (net/ipv4/af_inet.c:859)\n  __sys_sendto (net/socket.c:2206)\n\nFix this by setting skb-\u003edev = slave before calling\nnetdev_start_xmit(), so that tunnel xmit functions see the correct\nslave device with properly allocated tstats.","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/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit","id":"CVE-2026-23277","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"netfilter: nf_tables: always walk all pending catchall elements","id":"CVE-2026-23278"},"packages":[],"prev":{"headline":"net: add xmit recursion limit to tunnel xmit functions","id":"CVE-2026-23276"},"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":"2026-10-15","vendors":["Linux"]},"summary":"A NULL pointer dereference in the Linux kernel TEQL scheduler causes a system crash when transmitting through gretap tunnels.","url":"https://insights.sbomify.com/CVE-2026-23277/"}