{"api_version":"1","generated_at":"2026-08-02T08:18:35+00:00","cve":"CVE-2026-64543","urls":{"html":"https://cve.report/CVE-2026-64543","api":"https://cve.report/api/cve/CVE-2026-64543.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64543","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64543"},"summary":{"title":"tipc: fix use-after-free of the discoverer in tipc_disc_rcv()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix use-after-free of the discoverer in tipc_disc_rcv()\n\nbearer_disable() frees b->disc with tipc_disc_delete()'s plain kfree(),\nbut tipc_disc_rcv() still dereferences b->disc in RX softirq under\nrcu_read_lock() (tipc_udp_recv -> tipc_rcv -> tipc_disc_rcv).\n\nL2 bearers are safe thanks to the synchronize_net() in\ntipc_disable_l2_media(), but the UDP bearer defers that call to the\ncleanup_bearer() workqueue, so the discoverer is freed with no grace\nperiod:\n\n BUG: KASAN: slab-use-after-free in tipc_disc_rcv (net/tipc/discover.c:149)\n Read of size 8 at addr ffff88802348b728 by task poc_tipc/184\n <IRQ>\n  tipc_disc_rcv (net/tipc/discover.c:149)\n  tipc_rcv (net/tipc/node.c:2126)\n  tipc_udp_recv (net/tipc/udp_media.c:391)\n  udp_rcv (net/ipv4/udp.c:2643)\n  ip_local_deliver_finish (net/ipv4/ip_input.c:241)\n </IRQ>\n Freed by task 181:\n  kfree (mm/slub.c:6565)\n  bearer_disable (net/tipc/bearer.c:418)\n  tipc_nl_bearer_disable (net/tipc/bearer.c:1001)\n\nThe bearer is freed with kfree_rcu(); free the discoverer the same way.\nAdd an rcu_head to struct tipc_discoverer and free it and its skb from an\nRCU callback.\n\nBecause the RCU callback (tipc_disc_free_rcu) lives in module text, a\ncall_rcu() that is still pending when the tipc module is unloaded would\ninvoke a freed function. Add an rcu_barrier() to tipc_exit() after the\nbearer subsystem has been torn down, so all pending discoverer callbacks\nhave run before the module text goes away.\n\nReachable from an unprivileged user namespace: the TIPCv2 genl family is\nnetnsok and its bearer commands have no GENL_ADMIN_PERM. Needs CONFIG_TIPC\nand CONFIG_TIPC_MEDIA_UDP.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-27 21:17:06","updated_at":"2026-07-30 06:25:58"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/5e215bf1c47fdddf8203a0fe80a0ed594065f101","name":"https://git.kernel.org/stable/c/5e215bf1c47fdddf8203a0fe80a0ed594065f101","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1579342d71133da7f00daa02c75cebec7372097b","name":"https://git.kernel.org/stable/c/1579342d71133da7f00daa02c75cebec7372097b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2","name":"https://git.kernel.org/stable/c/a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b65289e1c3f352a9f92c6e19713ddd647e033253","name":"https://git.kernel.org/stable/c/b65289e1c3f352a9f92c6e19713ddd647e033253","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ec7d54d8cc1723921d671e3272b427c96366506f","name":"https://git.kernel.org/stable/c/ec7d54d8cc1723921d671e3272b427c96366506f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64543","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64543","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 5e215bf1c47fdddf8203a0fe80a0ed594065f101 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 ec7d54d8cc1723921d671e3272b427c96366506f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 b65289e1c3f352a9f92c6e19713ddd647e033253 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 1579342d71133da7f00daa02c75cebec7372097b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.17","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.17 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64543","cve":"CVE-2026-64543","epss":"0.001250000","percentile":"0.025940000","score_date":"2026-08-01","updated_at":"2026-08-02 00:11:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/tipc/core.c","net/tipc/discover.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"5e215bf1c47fdddf8203a0fe80a0ed594065f101","status":"affected","version":"25b0b9c4e835ffaa65b61c3efe2e28acf84d0259","versionType":"git"},{"lessThan":"ec7d54d8cc1723921d671e3272b427c96366506f","status":"affected","version":"25b0b9c4e835ffaa65b61c3efe2e28acf84d0259","versionType":"git"},{"lessThan":"a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2","status":"affected","version":"25b0b9c4e835ffaa65b61c3efe2e28acf84d0259","versionType":"git"},{"lessThan":"b65289e1c3f352a9f92c6e19713ddd647e033253","status":"affected","version":"25b0b9c4e835ffaa65b61c3efe2e28acf84d0259","versionType":"git"},{"lessThan":"1579342d71133da7f00daa02c75cebec7372097b","status":"affected","version":"25b0b9c4e835ffaa65b61c3efe2e28acf84d0259","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/tipc/core.c","net/tipc/discover.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.17"},{"lessThan":"4.17","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"4.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"4.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"4.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"4.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"4.17","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix use-after-free of the discoverer in tipc_disc_rcv()\n\nbearer_disable() frees b->disc with tipc_disc_delete()'s plain kfree(),\nbut tipc_disc_rcv() still dereferences b->disc in RX softirq under\nrcu_read_lock() (tipc_udp_recv -> tipc_rcv -> tipc_disc_rcv).\n\nL2 bearers are safe thanks to the synchronize_net() in\ntipc_disable_l2_media(), but the UDP bearer defers that call to the\ncleanup_bearer() workqueue, so the discoverer is freed with no grace\nperiod:\n\n BUG: KASAN: slab-use-after-free in tipc_disc_rcv (net/tipc/discover.c:149)\n Read of size 8 at addr ffff88802348b728 by task poc_tipc/184\n <IRQ>\n  tipc_disc_rcv (net/tipc/discover.c:149)\n  tipc_rcv (net/tipc/node.c:2126)\n  tipc_udp_recv (net/tipc/udp_media.c:391)\n  udp_rcv (net/ipv4/udp.c:2643)\n  ip_local_deliver_finish (net/ipv4/ip_input.c:241)\n </IRQ>\n Freed by task 181:\n  kfree (mm/slub.c:6565)\n  bearer_disable (net/tipc/bearer.c:418)\n  tipc_nl_bearer_disable (net/tipc/bearer.c:1001)\n\nThe bearer is freed with kfree_rcu(); free the discoverer the same way.\nAdd an rcu_head to struct tipc_discoverer and free it and its skb from an\nRCU callback.\n\nBecause the RCU callback (tipc_disc_free_rcu) lives in module text, a\ncall_rcu() that is still pending when the tipc module is unloaded would\ninvoke a freed function. Add an rcu_barrier() to tipc_exit() after the\nbearer subsystem has been torn down, so all pending discoverer callbacks\nhave run before the module text goes away.\n\nReachable from an unprivileged user namespace: the TIPCv2 genl family is\nnetnsok and its bearer commands have no GENL_ADMIN_PERM. Needs CONFIG_TIPC\nand CONFIG_TIPC_MEDIA_UDP."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-30T06:06:36.526Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/5e215bf1c47fdddf8203a0fe80a0ed594065f101"},{"url":"https://git.kernel.org/stable/c/ec7d54d8cc1723921d671e3272b427c96366506f"},{"url":"https://git.kernel.org/stable/c/a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2"},{"url":"https://git.kernel.org/stable/c/b65289e1c3f352a9f92c6e19713ddd647e033253"},{"url":"https://git.kernel.org/stable/c/1579342d71133da7f00daa02c75cebec7372097b"}],"title":"tipc: fix use-after-free of the discoverer in tipc_disc_rcv()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64543","datePublished":"2026-07-27T20:10:35.565Z","dateReserved":"2026-07-19T15:36:31.795Z","dateUpdated":"2026-07-30T06:06:36.526Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-27 21:17:06","lastModifiedDate":"2026-07-30 06:25:58","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64543","Ordinal":"1","Title":"tipc: fix use-after-free of the discoverer in tipc_disc_rcv()","CVE":"CVE-2026-64543","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64543","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix use-after-free of the discoverer in tipc_disc_rcv()\n\nbearer_disable() frees b->disc with tipc_disc_delete()'s plain kfree(),\nbut tipc_disc_rcv() still dereferences b->disc in RX softirq under\nrcu_read_lock() (tipc_udp_recv -> tipc_rcv -> tipc_disc_rcv).\n\nL2 bearers are safe thanks to the synchronize_net() in\ntipc_disable_l2_media(), but the UDP bearer defers that call to the\ncleanup_bearer() workqueue, so the discoverer is freed with no grace\nperiod:\n\n BUG: KASAN: slab-use-after-free in tipc_disc_rcv (net/tipc/discover.c:149)\n Read of size 8 at addr ffff88802348b728 by task poc_tipc/184\n <IRQ>\n  tipc_disc_rcv (net/tipc/discover.c:149)\n  tipc_rcv (net/tipc/node.c:2126)\n  tipc_udp_recv (net/tipc/udp_media.c:391)\n  udp_rcv (net/ipv4/udp.c:2643)\n  ip_local_deliver_finish (net/ipv4/ip_input.c:241)\n </IRQ>\n Freed by task 181:\n  kfree (mm/slub.c:6565)\n  bearer_disable (net/tipc/bearer.c:418)\n  tipc_nl_bearer_disable (net/tipc/bearer.c:1001)\n\nThe bearer is freed with kfree_rcu(); free the discoverer the same way.\nAdd an rcu_head to struct tipc_discoverer and free it and its skb from an\nRCU callback.\n\nBecause the RCU callback (tipc_disc_free_rcu) lives in module text, a\ncall_rcu() that is still pending when the tipc module is unloaded would\ninvoke a freed function. Add an rcu_barrier() to tipc_exit() after the\nbearer subsystem has been torn down, so all pending discoverer callbacks\nhave run before the module text goes away.\n\nReachable from an unprivileged user namespace: the TIPCv2 genl family is\nnetnsok and its bearer commands have no GENL_ADMIN_PERM. Needs CONFIG_TIPC\nand CONFIG_TIPC_MEDIA_UDP.","Type":"Description","Title":"tipc: fix use-after-free of the discoverer in tipc_disc_rcv()"}]}}}