{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "f7458934b0791c39a001e4d902fc3bf697b439b5"
            },
            {
              "fixed": "014c062d23c63ec77ef2cf17a0d9363c7441cc94"
            },
            {
              "fixed": "7ebc23ff03668042e0b0e4034bb1518d36198d9e"
            },
            {
              "fixed": "06d58b8d2f053ced82e01efaeb6e7c82891eed58"
            },
            {
              "fixed": "a5e385eeb2d6dbbbdebfa050e67c34734ae12693"
            },
            {
              "fixed": "5912cf1822fbe53ae275c147868740eb384a5d3e"
            },
            {
              "fixed": "e08665218040f8e312abe40f74543186f3c2c941"
            },
            {
              "fixed": "63488dba65ef91373ef616575b32eb0eb21459f4"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.14.0"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.152"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.104"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.45"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74659.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: mrp: fix uninitialised bytes on the wire\n\nbr_mrp_alloc_test_skb() builds MRP test frames on an skb from\ndev_alloc_skb(), which does not clear the linear data area.  On the MRA\nring-role branch the sub-option TLV header is appended with\n\n\tsub_tlv = skb_put(skb, sizeof(*sub_tlv));\n\tsub_tlv-\u003etype = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR;\n\nso sub_tlv-\u003elength is never written, and the two trailing alignment bytes\nare appended with a bare skb_put() that does not clear them either.  The\nneighbouring oui and sub_opt regions are explicitly zeroed, so three\nuninitialised bytes are left in every MRA MRP_Test frame that goes out.\n\nPut the sub-option TLV header and the alignment padding in a single\nskb_put_zero(), which clears both.  The AUTO_MGR sub-TLV carries no\npayload, so the zeroed length field is already the value it should have.",
  "id": "CVE-2026-74659",
  "modified": "2026-08-24T11:36:16.048426848Z",
  "published": "2026-08-22T15:32:32.926Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/014c062d23c63ec77ef2cf17a0d9363c7441cc94"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/06d58b8d2f053ced82e01efaeb6e7c82891eed58"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5912cf1822fbe53ae275c147868740eb384a5d3e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63488dba65ef91373ef616575b32eb0eb21459f4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7ebc23ff03668042e0b0e4034bb1518d36198d9e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5e385eeb2d6dbbbdebfa050e67c34734ae12693"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e08665218040f8e312abe40f74543186f3c2c941"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74659.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74659"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "net: bridge: mrp: fix uninitialised bytes on the wire"
}