FKIE_CVE-2026-74579

Vulnerability from fkie_nvd - Published: 2026-08-17 06:19 - Updated: 2026-08-17 06:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_payload: fix mask build for partial field offload nft_payload_offload_mask() builds the offload match mask for a payload expression that covers only part of a header field. For a partial IPv6 address match (field_len = 16, priv_len = 1) that shift is 1 << 120, which is undefined on the 32-bit int operand. It also trims only one word, so the remaining words stay 0xffffffff (and when priv_len is a multiple of 4 the trim is skipped entirely), leaving the mask covering more bytes than the rule matches. UBSAN: shift-out-of-bounds in net/netfilter/nft_payload.c:278:20 shift exponent 120 is too large for 32-bit type 'int' ... The match is byte-granular and struct nft_data is zero-initialised, so the correct mask is simply the first priv_len bytes set to 0xff. Set those bytes directly and drop the word/shift trimming; this removes the undefined shift and no longer over-masks the trailing bytes.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/16b553c46e347bc9de9946c4960654d5884a86de
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/39e88f28fb32bf02bd4b525c24c842c9cff5663d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/630295d5bba1d0e0f494cc459452eb0a0058c545
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a375d8ace807767f29f276b681b6324c74929b1d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b19b5d2e042c294e2cc1c908dc598f9d64015396
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nft_payload.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b19b5d2e042c294e2cc1c908dc598f9d64015396",
              "status": "affected",
              "version": "a5d45bc0dc50f9dd83703510e9804d813a9cac32",
              "versionType": "git"
            },
            {
              "lessThan": "a375d8ace807767f29f276b681b6324c74929b1d",
              "status": "affected",
              "version": "a5d45bc0dc50f9dd83703510e9804d813a9cac32",
              "versionType": "git"
            },
            {
              "lessThan": "16b553c46e347bc9de9946c4960654d5884a86de",
              "status": "affected",
              "version": "a5d45bc0dc50f9dd83703510e9804d813a9cac32",
              "versionType": "git"
            },
            {
              "lessThan": "630295d5bba1d0e0f494cc459452eb0a0058c545",
              "status": "affected",
              "version": "a5d45bc0dc50f9dd83703510e9804d813a9cac32",
              "versionType": "git"
            },
            {
              "lessThan": "39e88f28fb32bf02bd4b525c24c842c9cff5663d",
              "status": "affected",
              "version": "a5d45bc0dc50f9dd83703510e9804d813a9cac32",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "5c2b4b4f9fa5b765b927e361e3d310bcb5773015",
              "versionType": "git"
            },
            {
              "lessThan": "5.10",
              "status": "affected",
              "version": "5.9.14",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nft_payload.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.10"
            },
            {
              "lessThan": "5.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.151",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\nnetfilter: nft_payload: fix mask build for partial field offload\n\nnft_payload_offload_mask() builds the offload match mask for a payload\nexpression that covers only part of a header field.  For a partial IPv6\naddress match (field_len = 16, priv_len = 1) that shift is 1 \u003c\u003c 120, which\nis undefined on the 32-bit int operand.  It also trims only one word, so\nthe remaining words stay 0xffffffff (and when priv_len is a multiple of 4\nthe trim is skipped entirely), leaving the mask covering more bytes than\nthe rule matches.\n\n  UBSAN: shift-out-of-bounds in net/netfilter/nft_payload.c:278:20\n  shift exponent 120 is too large for 32-bit type \u0027int\u0027\n  ...\n\nThe match is byte-granular and struct nft_data is zero-initialised, so the\ncorrect mask is simply the first priv_len bytes set to 0xff. Set those\nbytes directly and drop the word/shift trimming; this removes the undefined\nshift and no longer over-masks the trailing bytes."
    }
  ],
  "id": "CVE-2026-74579",
  "lastModified": "2026-08-17T06:19:56.417",
  "metrics": {},
  "published": "2026-08-17T06:19:56.417",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/16b553c46e347bc9de9946c4960654d5884a86de"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/39e88f28fb32bf02bd4b525c24c842c9cff5663d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/630295d5bba1d0e0f494cc459452eb0a0058c545"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a375d8ace807767f29f276b681b6324c74929b1d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b19b5d2e042c294e2cc1c908dc598f9d64015396"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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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.

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Detection rules are retrieved from Rulezet.