FKIE_CVE-2026-98805

Vulnerability from fkie_nvd - Published: 2026-10-18 16:17 - Updated: 2026-10-30 13:21
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: tipc: prevent GCM nonce reuse on peer key changes TIPC can encrypt traffic between nodes using a different transmit key for each node. In this mode, the AES-GCM nonce for a packet sent to a known peer consists of a 32-bit prefix (a per-key salt XOR the peer's address) followed by a 64-bit counter. That counter is stored in the peer's RX crypto object. When the peer reports a change in which key it uses to receive packets, TIPC resets this counter. The sender can still be using the same TX key and salt, so subsequent packets reuse earlier nonces. This nonce reuse breaks confidentiality and exposes GCM's authentication key. This makes forgeries trivial: an attacker can exploit CTR malleability to alter captured ciphertexts and use the recovered authentication key to compute a valid tag for the modified ciphertext, under the same key and nonce. Use the TX key's existing aead->seqno counter instead. All encryptions using that key object share the same atomic counter, so concurrent encryptions get distinct nonce counter values. The counter survives key activation and peer reconnection, and peer key-status reports cannot reset it. This prevents those transitions from causing nonce reuse while the same TX key remains installed. The nonce format is unchanged, and receivers do not require consecutive counter values, so sharing the counter across peers remains compatible with existing receivers. A pre-existing check still invokes key revocation in the unlikely event that the counter wraps to zero.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/04d67f77fe3f9ec9c60db70773fb1696d0d58da8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0ff0ca5b514ceecad68b8682e072f373acc5acec
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/512ccd3d0e91e791fb37442aa0a2599aca19783d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5c8ce13c792e28d56f9ec3cd6728d8225bc0e3a2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/60e0c2aeaa605ff19ca4e65126a35643d4d7ee1c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7e5d5ac25e0857548cac963a2f850b19b2e1d59c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a85a3dce4b6c73ddaa1e9725b906249744bf7cf2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f74f100e49588c1dbdc6ab3ba9e2c67b36d015d0
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/tipc/crypto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "04d67f77fe3f9ec9c60db70773fb1696d0d58da8",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            },
            {
              "lessThan": "7e5d5ac25e0857548cac963a2f850b19b2e1d59c",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            },
            {
              "lessThan": "0ff0ca5b514ceecad68b8682e072f373acc5acec",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            },
            {
              "lessThan": "a85a3dce4b6c73ddaa1e9725b906249744bf7cf2",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            },
            {
              "lessThan": "5c8ce13c792e28d56f9ec3cd6728d8225bc0e3a2",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            },
            {
              "lessThan": "f74f100e49588c1dbdc6ab3ba9e2c67b36d015d0",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            },
            {
              "lessThan": "60e0c2aeaa605ff19ca4e65126a35643d4d7ee1c",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            },
            {
              "lessThan": "512ccd3d0e91e791fb37442aa0a2599aca19783d",
              "status": "affected",
              "version": "fc1b6d6de2208774efd2a20bf0daddb02d18b1e0",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/tipc/crypto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.5"
            },
            {
              "lessThan": "5.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.273",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.224",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: prevent GCM nonce reuse on peer key changes\n\nTIPC can encrypt traffic between nodes using a different transmit key\nfor each node. In this mode, the AES-GCM nonce for a packet sent to a\nknown peer consists of a 32-bit prefix (a per-key salt XOR the peer\u0027s\naddress) followed by a 64-bit counter. That counter is stored in the\npeer\u0027s RX crypto object. When the peer reports a change in which key\nit uses to receive packets, TIPC resets this counter. The sender can\nstill be using the same TX key and salt, so subsequent packets reuse\nearlier nonces. This nonce reuse breaks confidentiality and exposes\nGCM\u0027s authentication key. This makes forgeries trivial: an attacker\ncan exploit CTR malleability to alter captured ciphertexts and use the\nrecovered authentication key to compute a valid tag for the modified\nciphertext, under the same key and nonce.\n\nUse the TX key\u0027s existing aead-\u003eseqno counter instead. All encryptions\nusing that key object share the same atomic counter, so concurrent\nencryptions get distinct nonce counter values. The counter survives\nkey activation and peer reconnection, and peer key-status reports\ncannot reset it. This prevents those transitions from causing nonce\nreuse while the same TX key remains installed.\n\nThe nonce format is unchanged, and receivers do not require consecutive\ncounter values, so sharing the counter across peers remains compatible\nwith existing receivers. A pre-existing check still invokes key\nrevocation in the unlikely event that the counter wraps to zero."
    }
  ],
  "id": "CVE-2026-98805",
  "lastModified": "2026-10-30T13:21:28.507",
  "metrics": {},
  "published": "2026-10-18T16:17:34.567",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/04d67f77fe3f9ec9c60db70773fb1696d0d58da8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0ff0ca5b514ceecad68b8682e072f373acc5acec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/512ccd3d0e91e791fb37442aa0a2599aca19783d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5c8ce13c792e28d56f9ec3cd6728d8225bc0e3a2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/60e0c2aeaa605ff19ca4e65126a35643d4d7ee1c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7e5d5ac25e0857548cac963a2f850b19b2e1d59c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a85a3dce4b6c73ddaa1e9725b906249744bf7cf2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f74f100e49588c1dbdc6ab3ba9e2c67b36d015d0"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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