# CVE-2026-64371: proc: protect ptrace_may_access() with exec_update_lock (part 1)

Status: published. Published: 2026-07-25. Updated: 2026-11-10.

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

proc: protect ptrace_may_access() with exec_update_lock (part 1)

Fix the easy cases where procfs currently calls ptrace_may_access() without
exec_update_lock protection, where the fix is to simply add the extra lock
or use mm_access():

 - do_task_stat(): grab exec_update_lock
 - proc_pid_wchan(): grab exec_update_lock
 - proc_map_files_lookup(): use mm_access() instead of get_task_mm()
 - proc_map_files_readdir(): use mm_access() instead of get_task_mm()
 - proc_ns_get_link(): grab exec_update_lock
 - proc_ns_readlink(): grab exec_update_lock

## Remediation

- 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) — https://git.kernel.org/stable/c/4bfe8c481846cee52473a2f7d7b30ee8e6749fc4
- 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) — https://git.kernel.org/stable/c/6650527444dadc63d84aa939d14ecba4fadb2f69
- 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) — https://git.kernel.org/stable/c/7456ae990a9738962b33146916fabca62ae3d4e0
- 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) — https://git.kernel.org/stable/c/ae1e630bcaac739f625822078edbaea98366930d
- 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) — https://git.kernel.org/stable/c/bb43679356f1f2a4c6b1c88aec4f021e5b5c74e9
- 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) — https://git.kernel.org/stable/c/c1cfd63326f5d09999134e9052c353faf738286e
- 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) — https://git.kernel.org/stable/c/d54f14655fd7d7b293698a8b6918563c4c0465e7
- 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) — https://git.kernel.org/stable/c/f9b4b03ccc9c69bf7f7298d4559906ebea7143b3

## Affected products and versions

- Linux / Linux: ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < ae1e630bcaac739f625822078edbaea98366930d (affected, git); ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < d54f14655fd7d7b293698a8b6918563c4c0465e7 (affected, git); ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < bb43679356f1f2a4c6b1c88aec4f021e5b5c74e9 (affected, git); ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < 7456ae990a9738962b33146916fabca62ae3d4e0 (affected, git); ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < 4bfe8c481846cee52473a2f7d7b30ee8e6749fc4 (affected, git); ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < f9b4b03ccc9c69bf7f7298d4559906ebea7143b3 (affected, git); ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < c1cfd63326f5d09999134e9052c353faf738286e (affected, git); ≥ f83ce3e6b02d5e48b3a43b001390e2b58820389d; < 6650527444dadc63d84aa939d14ecba4fadb2f69 (affected, git); 6b06d6282100dd5aacf7d45443d651a1995bd9c4 (affected, git); 334ed22054b2ec8477e4409e214fc139cf937ef6 (affected, git); ≥ 2.6.27.23; < 2.6.28 (affected, semver); ≥ 2.6.29.3; < 2.6.30 (affected, semver). Source: CNA: Linux
- Linux / Linux: 2.6.30 (affected); ≥ 0; < 2.6.30 (unaffected, semver); ≥ 5.10.261; ≤ 5.10.* (unaffected, semver); ≥ 5.15.212; ≤ 5.15.* (unaffected, semver); ≥ 6.1.178; ≤ 6.1.* (unaffected, semver); ≥ 6.6.145; ≤ 6.6.* (unaffected, semver); ≥ 6.12.97; ≤ 6.12.* (unaffected, semver); ≥ 6.18.40; ≤ 6.18.* (unaffected, semver); ≥ 7.1.4; ≤ 7.1.* (unaffected, semver); ≥ 7.2; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "2.6.28",
            "versionStartIncluding": "2.6.27.23",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "2.6.30",
            "versionStartIncluding": "2.6.29.3",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "5.10.261",
            "versionStartIncluding": "2.6.30.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "5.15.212",
            "versionStartIncluding": "5.11",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.1.178",
            "versionStartIncluding": "5.16",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.6.145",
            "versionStartIncluding": "6.2",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.12.97",
            "versionStartIncluding": "6.7",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.18.40",
            "versionStartIncluding": "6.13",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "7.1.4",
            "versionStartIncluding": "6.19",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.30:-:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.30:rc5:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.30:rc6:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.30:rc7:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.30:rc8:*:*:*:*:*:*",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H; source: NVD: nvd@nist.gov

- CISA KEV: No listing in collected sources

- EPSS: 0.13% as of 2026-11-09; percentile 2.54%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

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

## References

- https://git.kernel.org/stable/c/ae1e630bcaac739f625822078edbaea98366930d (CNA: Linux)

- https://git.kernel.org/stable/c/d54f14655fd7d7b293698a8b6918563c4c0465e7 (CNA: Linux)

- https://git.kernel.org/stable/c/bb43679356f1f2a4c6b1c88aec4f021e5b5c74e9 (CNA: Linux)

- https://git.kernel.org/stable/c/7456ae990a9738962b33146916fabca62ae3d4e0 (CNA: Linux)

- https://git.kernel.org/stable/c/4bfe8c481846cee52473a2f7d7b30ee8e6749fc4 (CNA: Linux)

- https://git.kernel.org/stable/c/f9b4b03ccc9c69bf7f7298d4559906ebea7143b3 (CNA: Linux)

- https://git.kernel.org/stable/c/c1cfd63326f5d09999134e9052c353faf738286e (CNA: Linux)

- https://git.kernel.org/stable/c/6650527444dadc63d84aa939d14ecba4fadb2f69 (CNA: Linux)

- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (ADP: siemens-SADP)

- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (ADP: siemens-SADP)

- https://git.kernel.org/stable/c/4bfe8c481846cee52473a2f7d7b30ee8e6749fc4 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/6650527444dadc63d84aa939d14ecba4fadb2f69 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/7456ae990a9738962b33146916fabca62ae3d4e0 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/ae1e630bcaac739f625822078edbaea98366930d (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/bb43679356f1f2a4c6b1c88aec4f021e5b5c74e9 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/c1cfd63326f5d09999134e9052c353faf738286e (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/d54f14655fd7d7b293698a8b6918563c4c0465e7 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/f9b4b03ccc9c69bf7f7298d4559906ebea7143b3 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (0b142b55-0307-4c5a-b3c9-f314f3fb7c5e; Third Party Advisory)

- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (0b142b55-0307-4c5a-b3c9-f314f3fb7c5e)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-64371; retrieved 2026-11-10; source updated 2026-11-10

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64371; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-64371; retrieved 2026-11-10; source updated Not reported

Revision: 7a80b4f289a41d29d57f80a703be220e1a22fdced4935195d8d2bf3e1d8ce9e5

Canonical: https://y2.dev/cve/CVE-2026-64371

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