CVE-2026-89897 (GCVE-0-2026-89897)
Vulnerability from cvelistv5
Published
2026-09-16 10:31
Modified
2026-10-19 08:54
Severity ?
7.5 (High) - CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: media: cec: Serialize exclusive follower delivery cec_receive_notify() reads the exclusive follower pointer without the adapter lock. Serialize the no-follower check and message delivery against mode changes and release.
References
Impacted products
Vendor Product Version
Linux Linux Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
Version: 9881fe0ca187c213eb3a6a8e78e45ad4d1cec171
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/media/cec/core/cec-adap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "efc829b4b937f98c4467bffe9243f756b7cfbf7f",
              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            },
            {
              "lessThan": "cac577854826950dda4d53569728b1da6c1425d5",
              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            },
            {
              "lessThan": "4b532b271c91790b7ab661cd488a7ad36f5c4f6b",
              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            },
            {
              "lessThan": "271e57a936dcdbaecb4b1bd005d9a285bbe60ab4",
              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            },
            {
              "lessThan": "df941e6851da17fc53c7f6af2bdcc7383d17babc",
              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            },
            {
              "lessThan": "1924d0788caa6c66fd320dd4704fae99487fd2c7",
              "status": "affected",
              "version": "9881fe0ca187c213eb3a6a8e78e45ad4d1cec171",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/media/cec/core/cec-adap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.8"
            },
            {
              "lessThan": "4.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.270",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.221",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.188",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.110",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.51",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.5",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "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\u0027d 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": {
        "dateUpdated": "2026-10-19T08:54:30.169Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "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"
        }
      ],
      "title": "media: cec: Serialize exclusive follower delivery",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89897",
    "datePublished": "2026-09-16T10:31:58.184Z",
    "dateReserved": "2026-09-11T19:38:34.773Z",
    "dateUpdated": "2026-10-19T08:54:30.169Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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