GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-74278 (GCVE-0-2026-74278)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:57 – Updated: 2026-08-17 05:16
VLAI
Title
ALSA: seq: Fix kernel heap address leak in bounce_error_event()
Summary
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix kernel heap address leak in bounce_error_event() The comment above bounce_error_event() documents that user clients should receive SNDRV_SEQ_EVENT_BOUNCE with the original event embedded as variable-length data, while kernel clients should receive SNDRV_SEQ_EVENT_KERNEL_ERROR with a quoted kernel pointer. However, the implementation unconditionally uses SNDRV_SEQ_EVENT_KERNEL_ERROR with data.quote.event set to the raw struct snd_seq_event pointer for all clients. When a bounce error event is delivered to a USER_CLIENT via snd_seq_read(), the kernel heap address in data.quote.event is exposed to userspace through copy_to_user() in the fixed-length branch. This is a distinct leak path from the one addressed by commit 705dd6dcbc0e ("ALSA: seq: Clear variable event pointer on read"), which sanitizes data.ext.ptr in the variable-length branch of snd_seq_read(). The bounce_error_event() leak uses fixed-length events that take the else branch where no sanitization occurs. Differentiate the bounce event by client type. For USER_CLIENT, send SNDRV_SEQ_EVENT_BOUNCE with SNDRV_SEQ_EVENT_LENGTH_VARIABLE and data.ext pointing to the original event. The variable-length path in snd_seq_event_dup() copies the event data into chained cells, and snd_seq_expand_var_event() copies only the content -- never the pointer -- to userspace. For KERNEL_CLIENT, keep the existing SNDRV_SEQ_EVENT_KERNEL_ERROR behavior with the quoted pointer.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 93d260ce43a81df579c98bee92b91316df9c1c57 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < dae23c545eb5a2be3b27a82fd0f611894fb8ab69 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 0527a56cb327021cb73167cfddf0e49efa043500 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < efc86691e4d8083d9e380ea95042c2cf679f65fd (git)
guessed Create a notification for this product.
Linux Linux Affected: 2.6.12
Unaffected: 0 , < 2.6.12 (semver)
Unaffected: 6.12.97 , ≤ 6.12.* (semver)
Unaffected: 6.18.40 , ≤ 6.18.* (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/core/seq/seq_clientmgr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "93d260ce43a81df579c98bee92b91316df9c1c57",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "dae23c545eb5a2be3b27a82fd0f611894fb8ab69",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "0527a56cb327021cb73167cfddf0e49efa043500",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "efc86691e4d8083d9e380ea95042c2cf679f65fd",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/core/seq/seq_clientmgr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "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",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Fix kernel heap address leak in bounce_error_event()\n\nThe comment above bounce_error_event() documents that user clients\nshould receive SNDRV_SEQ_EVENT_BOUNCE with the original event embedded\nas variable-length data, while kernel clients should receive\nSNDRV_SEQ_EVENT_KERNEL_ERROR with a quoted kernel pointer.\n\nHowever, the implementation unconditionally uses\nSNDRV_SEQ_EVENT_KERNEL_ERROR with data.quote.event set to the raw\nstruct snd_seq_event pointer for all clients.  When a bounce error\nevent is delivered to a USER_CLIENT via snd_seq_read(), the kernel\nheap address in data.quote.event is exposed to userspace through\ncopy_to_user() in the fixed-length branch.\n\nThis is a distinct leak path from the one addressed by commit\n705dd6dcbc0e (\"ALSA: seq: Clear variable event pointer on read\"),\nwhich sanitizes data.ext.ptr in the variable-length branch of\nsnd_seq_read().  The bounce_error_event() leak uses fixed-length\nevents that take the else branch where no sanitization occurs.\n\nDifferentiate the bounce event by client type.  For USER_CLIENT,\nsend SNDRV_SEQ_EVENT_BOUNCE with SNDRV_SEQ_EVENT_LENGTH_VARIABLE\nand data.ext pointing to the original event.  The variable-length\npath in snd_seq_event_dup() copies the event data into chained\ncells, and snd_seq_expand_var_event() copies only the content --\nnever the pointer -- to userspace.  For KERNEL_CLIENT, keep the\nexisting SNDRV_SEQ_EVENT_KERNEL_ERROR behavior with the quoted\npointer."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:16:23.206Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/93d260ce43a81df579c98bee92b91316df9c1c57"
        },
        {
          "url": "https://git.kernel.org/stable/c/dae23c545eb5a2be3b27a82fd0f611894fb8ab69"
        },
        {
          "url": "https://git.kernel.org/stable/c/0527a56cb327021cb73167cfddf0e49efa043500"
        },
        {
          "url": "https://git.kernel.org/stable/c/efc86691e4d8083d9e380ea95042c2cf679f65fd"
        }
      ],
      "title": "ALSA: seq: Fix kernel heap address leak in bounce_error_event()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74278",
    "datePublished": "2026-08-15T05:57:49.475Z",
    "dateReserved": "2026-08-15T05:44:03.880Z",
    "dateUpdated": "2026-08-17T05:16:23.206Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-74278",
      "date": "2026-09-11",
      "epss": "0.00168",
      "percentile": "0.06336"
    },
    "microsoft_vex": {
      "current_release_date": "2026-08-23T15:01:48.000Z",
      "cve": "CVE-2026-74278",
      "id": "msrc_CVE-2026-74278",
      "initial_release_date": "2026-08-23T15:01:48.000Z",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "ALSA: seq: Fix kernel heap address leak in bounce_error_event()",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74278.json",
      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-74278\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T06:22:27.213\",\"lastModified\":\"2026-08-17T06:19:21.510\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nALSA: seq: Fix kernel heap address leak in bounce_error_event()\\n\\nThe comment above bounce_error_event() documents that user clients\\nshould receive SNDRV_SEQ_EVENT_BOUNCE with the original event embedded\\nas variable-length data, while kernel clients should receive\\nSNDRV_SEQ_EVENT_KERNEL_ERROR with a quoted kernel pointer.\\n\\nHowever, the implementation unconditionally uses\\nSNDRV_SEQ_EVENT_KERNEL_ERROR with data.quote.event set to the raw\\nstruct snd_seq_event pointer for all clients.  When a bounce error\\nevent is delivered to a USER_CLIENT via snd_seq_read(), the kernel\\nheap address in data.quote.event is exposed to userspace through\\ncopy_to_user() in the fixed-length branch.\\n\\nThis is a distinct leak path from the one addressed by commit\\n705dd6dcbc0e (\\\"ALSA: seq: Clear variable event pointer on read\\\"),\\nwhich sanitizes data.ext.ptr in the variable-length branch of\\nsnd_seq_read().  The bounce_error_event() leak uses fixed-length\\nevents that take the else branch where no sanitization occurs.\\n\\nDifferentiate the bounce event by client type.  For USER_CLIENT,\\nsend SNDRV_SEQ_EVENT_BOUNCE with SNDRV_SEQ_EVENT_LENGTH_VARIABLE\\nand data.ext pointing to the original event.  The variable-length\\npath in snd_seq_event_dup() copies the event data into chained\\ncells, and snd_seq_expand_var_event() copies only the content --\\nnever the pointer -- to userspace.  For KERNEL_CLIENT, keep the\\nexisting SNDRV_SEQ_EVENT_KERNEL_ERROR behavior with the quoted\\npointer.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"sound/core/seq/seq_clientmgr.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"93d260ce43a81df579c98bee92b91316df9c1c57\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"dae23c545eb5a2be3b27a82fd0f611894fb8ab69\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"0527a56cb327021cb73167cfddf0e49efa043500\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"efc86691e4d8083d9e380ea95042c2cf679f65fd\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"sound/core/seq/seq_clientmgr.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.12\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.12\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.97\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0527a56cb327021cb73167cfddf0e49efa043500\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/93d260ce43a81df579c98bee92b91316df9c1c57\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/dae23c545eb5a2be3b27a82fd0f611894fb8ab69\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/efc86691e4d8083d9e380ea95042c2cf679f65fd\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-20T15:04:32+00:00",
      "cve": "CVE-2026-74278",
      "id": "CVE-2026-74278",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ALSA: seq: Fix kernel heap address leak in bounce_error_event()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74278.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "low",
      "current_release_date": "2026-09-03T00:07:10Z",
      "cve": "CVE-2026-74278",
      "id": "CVE-2026-74278",
      "initial_release_date": "2026-09-03T00:07:10Z",
      "product_status:known_affected": "286",
      "product_status:known_not_affected": "76",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-74278",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-74278.json",
      "version": "2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.