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CVE-2026-53236

tcp: restrict SO_ATTACH_FILTER to priv users

published

In the Linux kernel, the following vulnerability has been resolved: tcp: restrict SO_ATTACH_FILTER to priv users This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers.

Technical severity5.5 mediumCVSS 3.1 · NVD: [email protected]

Published2026-06-25Source updated 2026-11-10

Collected2026-11-103 attributed sources

Fixes and workarounds

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
Linux Linux	≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 3747de241a66ef2c7032d2cc2b826a47c5fa0f6a (affected, git) ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba (affected, git) ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 82b3e7ce10c53fc12aab8904745603efc74f8c07 (affected, git) ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < ede69b8f6670600e534591664584f810d7c385f9 (affected, git) ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < c68517a3e18e20997808821c5559d0cba4d776c1 (affected, git) ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 5d39580f68e6ddeedd15e587282207489dfb3da2 (affected, git) Other versions: unaffected	CNA: Linux
Linux Linux	2.6.12 (affected) ≥ 0; < 2.6.12 (unaffected, semver) ≥ 6.1.176; ≤ 6.1.* (unaffected, semver) ≥ 6.6.143; ≤ 6.6.* (unaffected, semver) ≥ 6.12.94; ≤ 6.12.* (unaffected, semver) ≥ 6.18.36; ≤ 6.18.* (unaffected, semver) ≥ 7.0.13; ≤ 7.0.* (unaffected, semver) ≥ 7.1; ≤ * (unaffected, original_commit_for_fix) Other versions: affected	CNA: Linux
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) Siemens	≥ V3.1.6; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) Siemens	≥ V3.1.7; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) Siemens	≥ V3.1.6; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) Siemens	≥ V3.1.7; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) Siemens	≥ V3.1.6; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) Siemens	≥ V3.1.7; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) Siemens	≥ V3.1.6; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) Siemens	≥ V3.1.7; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem Siemens	≥ 0; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) Siemens	≥ V3.1.6; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) Siemens	≥ V3.1.7; < * (affected, custom) Other versions: unknown	ADP: siemens-SADP

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

NVD applicability configurations (1)

These expressions retain AND/OR operators, negation, and required environmental products. A listed product is not sufficient to establish exposure when additional conditions apply.

[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.1.176",
            "versionStartIncluding": "2.6.12.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.6.143",
            "versionStartIncluding": "6.2",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.12.94",
            "versionStartIncluding": "6.7",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.18.36",
            "versionStartIncluding": "6.13",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "7.0.13",
            "versionStartIncluding": "6.19",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:*",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 5.5 medium	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`	NVD: [email protected]

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://git.kernel.org/stable/c/3747de241a66ef2c7032d2cc2b826a47c5fa0f6aCNA: Linux
https://git.kernel.org/stable/c/ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51baCNA: Linux
https://git.kernel.org/stable/c/82b3e7ce10c53fc12aab8904745603efc74f8c07CNA: Linux
https://git.kernel.org/stable/c/ede69b8f6670600e534591664584f810d7c385f9CNA: Linux
https://git.kernel.org/stable/c/c68517a3e18e20997808821c5559d0cba4d776c1CNA: Linux
https://git.kernel.org/stable/c/5d39580f68e6ddeedd15e587282207489dfb3da2CNA: Linux
https://cert-portal.siemens.com/productcert/html/ssa-019113.htmlADP: siemens-SADP
https://cert-portal.siemens.com/productcert/html/ssa-457936.htmlADP: siemens-SADP
https://cert-portal.siemens.com/productcert/html/ssa-784472.htmlADP: siemens-SADP
https://git.kernel.org/stable/c/3747de241a66ef2c7032d2cc2b826a47c5fa0f6a416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://git.kernel.org/stable/c/5d39580f68e6ddeedd15e587282207489dfb3da2416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://git.kernel.org/stable/c/82b3e7ce10c53fc12aab8904745603efc74f8c07416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://git.kernel.org/stable/c/c68517a3e18e20997808821c5559d0cba4d776c1416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://git.kernel.org/stable/c/ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://git.kernel.org/stable/c/ede69b8f6670600e534591664584f810d7c385f9416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://cert-portal.siemens.com/productcert/html/ssa-019113.html0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-457936.html0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-784472.html0b142b55-0307-4c5a-b3c9-f314f3fb7c5e

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