CVE-2026-98850

Status: ReceivedUnscored—
Severity—Unscored
Exploitation probability0.16 %higher than 4% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

In the Linux kernel, the following vulnerability has been resolved:

net/packet: prevent TX_RING byte count overflow

tpacket_snd() drains every SEND_REQUEST frame in a TX ring and adds each valid packet length to the signed int len_sum. Userspace can recycle completed frames concurrently, so a single blocking send call is not bounded by the ring size.

After enough successful transmissions len_sum wraps into the negative range. In particular, 65536 65535-byte frames followed by a 65007-byte frame produce 0xfffffdef, or -EIOCBQUEUED. sock_sendmsg_nosec() treats that as an impossible return and triggers a BUG. On systems configured to panic on oops, a CAP_NET_RAW holder can panic the host kernel.

Read full descriptionShow less

Stop before the next frame would make the byte count exceed INT_MAX. The positive short count leaves that frame pending for a later send call.

A two-thread TPACKET_V2 reproducer triggered the BUG on an arm64 build of Linux 7.3-rc4. With this change, the same reproducer returned the expected positive short count without an oops.

CVSS

NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.16 %
Percentile among all scored CVEs
4
Score date
10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

References

Show 4 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-98850",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1",
              "lessThan": "be12b221c0301111eeb023be04add3c6ad7c21fe",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1",
              "lessThan": "69ca64bbb528898916f309552053c32a04a36ebc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1",
              "lessThan": "9fd63d284e251332f4874ef9023cde472f315f86",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1",
              "lessThan": "2cf81fc9505b148b1b70068303ea6ea4b1212403",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/packet/af_packet.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.31"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "2.6.31",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/packet/af_packet.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-10-18T16:17:39.390",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2cf81fc9505b148b1b70068303ea6ea4b1212403",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/69ca64bbb528898916f309552053c32a04a36ebc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9fd63d284e251332f4874ef9023cde472f315f86",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/be12b221c0301111eeb023be04add3c6ad7c21fe",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: prevent TX_RING byte count overflow\n\ntpacket_snd() drains every SEND_REQUEST frame in a TX ring and adds\neach valid packet length to the signed int len_sum. Userspace can\nrecycle completed frames concurrently, so a single blocking send call\nis not bounded by the ring size.\n\nAfter enough successful transmissions len_sum wraps into the negative\nrange. In particular, 65536 65535-byte frames followed by a 65007-byte\nframe produce 0xfffffdef, or -EIOCBQUEUED. sock_sendmsg_nosec() treats\nthat as an impossible return and triggers a BUG. On systems configured\nto panic on oops, a CAP_NET_RAW holder can panic the host kernel.\n\nStop before the next frame would make the byte count exceed INT_MAX.\nThe positive short count leaves that frame pending for a later send\ncall.\n\nA two-thread TPACKET_V2 reproducer triggered the BUG on an arm64 build\nof Linux 7.3-rc4. With this change, the same reproducer returned the\nexpected positive short count without an oops."
    }
  ],
  "lastModified": "2026-10-19T10:19:49.103",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}