Vulnerability-Lookup

FKIE_CVE-2026-43198

Vulnerability from fkie_nvd - Published: 2026-05-06 12:16 - Updated: 2026-05-11 20:12

Severity ?

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: tcp: fix potential race in tcp_v6_syn_recv_sock() Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock() is done too late. After tcp_v4_syn_recv_sock(), the child socket is already visible from TCP ehash table and other cpus might use it. Since newinet->pinet6 is still pointing to the listener ipv6_pinfo bad things can happen as syzbot found. Move the problematic code in tcp_v6_mapped_child_init() and call this new helper from tcp_v4_syn_recv_sock() before the ehash insertion. This allows the removal of one tcp_sync_mss(), since tcp_v4_syn_recv_sock() will call it with the correct context.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deae	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fe89b2f05b854847784f91127319172945c1fadd	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	7.0

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "0565F020-6741-42F7-A887-6FEBC0627804",
              "versionEndExcluding": "6.18.16",
              "versionStartIncluding": "2.6.12.1",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67",
              "versionEndExcluding": "6.19.6",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*",
              "matchCriteriaId": "6F62EECE-8FB1-4D57-85D8-CB9E23CF313C",
              "vulnerable": true
            },
            {
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              "matchCriteriaId": "4F76C298-81DC-43E4-8FC9-DC005A2116EF",
              "vulnerable": true
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              "matchCriteriaId": "0AB349B2-3F78-4197-882B-90ADB3BF645A",
              "vulnerable": true
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            },
            {
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              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16",
              "vulnerable": true
            }
          ],
          "negate": false,
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        }
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: fix potential race in tcp_v6_syn_recv_sock()\n\nCode in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()\nis done too late.\n\nAfter tcp_v4_syn_recv_sock(), the child socket is already visible\nfrom TCP ehash table and other cpus might use it.\n\nSince newinet-\u003epinet6 is still pointing to the listener ipv6_pinfo\nbad things can happen as syzbot found.\n\nMove the problematic code in tcp_v6_mapped_child_init()\nand call this new helper from tcp_v4_syn_recv_sock() before\nthe ehash insertion.\n\nThis allows the removal of one tcp_sync_mss(), since\ntcp_v4_syn_recv_sock() will call it with the correct\ncontext."
    }
  ],
  "id": "CVE-2026-43198",
  "lastModified": "2026-05-11T20:12:11.740",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-06T12:16:38.857",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      ],
      "url": "https://git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deae"
    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    }
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-43198 (GCVE-0-2026-43198)

Vulnerability from cvelistv5 – Published: 2026-05-06 11:28 – Updated: 2026-05-11 22:19

Title

tcp: fix potential race in tcp_v6_syn_recv_sock()

Summary

Severity ?

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/fe89b2f05b8548477…
https://git.kernel.org/stable/c/7178e2a8027423b2a…
https://git.kernel.org/stable/c/858d2a4f67ff69e64…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < fe89b2f05b854847784f91127319172945c1fadd (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 7178e2a8027423b2af17ab95df73a749a5b72e5b (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 858d2a4f67ff69e645a43487ef7ea7f28f06deae (git)
Linux	Linux	Affected: 2.6.12 Unaffected: 0 , < 2.6.12 (semver) Unaffected: 6.18.16 , ≤ 6.18.* (semver) Unaffected: 6.19.6 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/inet_connection_sock.h",
            "include/net/tcp.h",
            "net/ipv4/syncookies.c",
            "net/ipv4/tcp_fastopen.c",
            "net/ipv4/tcp_ipv4.c",
            "net/ipv4/tcp_minisocks.c",
            "net/ipv6/tcp_ipv6.c",
            "net/mptcp/subflow.c",
            "net/smc/af_smc.c"
          ],
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          "vendor": "Linux",
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            "net/ipv4/syncookies.c",
            "net/ipv4/tcp_fastopen.c",
            "net/ipv4/tcp_ipv4.c",
            "net/ipv4/tcp_minisocks.c",
            "net/ipv6/tcp_ipv6.c",
            "net/mptcp/subflow.c",
            "net/smc/af_smc.c"
          ],
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          "vendor": "Linux",
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              "status": "unaffected",
              "version": "0",
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              "status": "unaffected",
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              "status": "unaffected",
              "version": "6.19.6",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
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        }
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    "dateReserved": "2026-05-01T14:12:55.992Z",
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}

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.

Action not permitted

FKIE_CVE-2026-43198

CVE-2026-43198 (GCVE-0-2026-43198)

Tags

Sightings

Nomenclature