{"id":"CVE-2026-89897","state":"PUBLISHED","title":"media: cec: Serialize exclusive follower delivery","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cec: Serialize exclusive follower delivery\n\ncec_receive_notify() reads the exclusive follower pointer without the\nadapter lock. Serialize the no-follower check and message delivery\nagainst mode changes and release.","publishedAt":"2026-09-16T10:31:58.184Z","updatedAt":"2026-10-19T08:54:30.169Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"efc829b4b937f98c4467bffe9243f756b7cfbf7f","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"cac577854826950dda4d53569728b1da6c1425d5","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"4b532b271c91790b7ab661cd488a7ad36f5c4f6b","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"271e57a936dcdbaecb4b1bd005d9a285bbe60ab4","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"df941e6851da17fc53c7f6af2bdcc7383d17babc","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"5c62095acc2a952099688774513c4a637bcdb2b5","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"ae614f48712156fb0f55b207338d48d422c58bc0","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"1924d0788caa6c66fd320dd4704fae99487fd2c7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/cec/core/cec-adap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.8","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/cec/core/cec-adap.c"]}],"references":["https://git.kernel.org/stable/c/efc829b4b937f98c4467bffe9243f756b7cfbf7f","https://git.kernel.org/stable/c/cac577854826950dda4d53569728b1da6c1425d5","https://git.kernel.org/stable/c/4b532b271c91790b7ab661cd488a7ad36f5c4f6b","https://git.kernel.org/stable/c/271e57a936dcdbaecb4b1bd005d9a285bbe60ab4","https://git.kernel.org/stable/c/df941e6851da17fc53c7f6af2bdcc7383d17babc","https://git.kernel.org/stable/c/5c62095acc2a952099688774513c4a637bcdb2b5","https://git.kernel.org/stable/c/ae614f48712156fb0f55b207338d48d422c58bc0","https://git.kernel.org/stable/c/1924d0788caa6c66fd320dd4704fae99487fd2c7"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89897.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89897","state":"PUBLISHED","datePublished":"2026-09-16T10:31:58.184Z","dateUpdated":"2026-10-19T08:54:30.169Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.773Z"},"containers":{"cna":{"title":"media: cec: Serialize exclusive follower delivery","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cec: Serialize exclusive follower delivery\n\ncec_receive_notify() reads the exclusive follower pointer without the\nadapter lock. Serialize the no-follower check and message delivery\nagainst mode changes and release."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"efc829b4b937f98c4467bffe9243f756b7cfbf7f","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"cac577854826950dda4d53569728b1da6c1425d5","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"4b532b271c91790b7ab661cd488a7ad36f5c4f6b","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"271e57a936dcdbaecb4b1bd005d9a285bbe60ab4","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"df941e6851da17fc53c7f6af2bdcc7383d17babc","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"5c62095acc2a952099688774513c4a637bcdb2b5","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"ae614f48712156fb0f55b207338d48d422c58bc0","versionType":"git"},{"version":"9881fe0ca187c213eb3a6a8e78e45ad4d1cec171","status":"affected","lessThan":"1924d0788caa6c66fd320dd4704fae99487fd2c7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/cec/core/cec-adap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.8","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/cec/core/cec-adap.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/efc829b4b937f98c4467bffe9243f756b7cfbf7f"},{"url":"https://git.kernel.org/stable/c/cac577854826950dda4d53569728b1da6c1425d5"},{"url":"https://git.kernel.org/stable/c/4b532b271c91790b7ab661cd488a7ad36f5c4f6b"},{"url":"https://git.kernel.org/stable/c/271e57a936dcdbaecb4b1bd005d9a285bbe60ab4"},{"url":"https://git.kernel.org/stable/c/df941e6851da17fc53c7f6af2bdcc7383d17babc"},{"url":"https://git.kernel.org/stable/c/5c62095acc2a952099688774513c4a637bcdb2b5"},{"url":"https://git.kernel.org/stable/c/ae614f48712156fb0f55b207338d48d422c58bc0"},{"url":"https://git.kernel.org/stable/c/1924d0788caa6c66fd320dd4704fae99487fd2c7"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - cec_receive_notify() runs from cec_received_msg_ts() on HDMI-CEC frames a peer places on the shared CEC line. HDMI-CEC is a multi-drop bus among TVs, AVRs, streaming sticks, and conference or automotive HDMI sources, matching CAN/Bluetooth adjacent-segment scoring rather than Internet-routable Network.\nAC:H - The use-after-free requires cec_release() to kfree the exclusive-follower cec_fh after the unlocked pointer load in cec_receive_notify(). A CEC peer can flood receive but cannot close that filehandle, so success depends on concurrent local teardown the attacker cannot initiate.\nPR:N - HDMI-CEC has no authentication. Any device on the same CEC bus can emit frames that the adapter delivers into cec_received_msg_ts() with no Linux account, capability, or user-namespace check on the host.\nUI:N - Once the adapter is configured and receiving, which is normal for TVs, Android HDMI-CEC, SBCs, and automotive head units that claim a logical address at boot, RX delivery and any concurrent follower close run without a mount, prompt, or other interactive victim step.\nS:U - The use-after-free is of the kmalloc'd struct cec_fh inside the host kernel CEC core and does not cross a VM, IOMMU, or other separate security-authority boundary.\nC:H - After cec_release() kfree()s the exclusive follower, cec_queue_msg_fh() still locks and walks lists on the dangling cec_fh. That kernel heap use-after-free enables disclosure of reused object contents.\nI:H - cec_queue_msg_fh() writes the freed filehandle via mutex operations, list_add_tail of a new cec_msg_entry, and wake_up_interruptible, a heap use-after-free write and control-flow hijack primitive.\nA:H - Using a freed cec_fh from the receive path causes a kernel oops or panic even when not fully exploited for code execution, taking down the host."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:54:30.169Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}