# CVE-2026-52970: netfilter: nft_ct: fix missing expect put in obj eval

Status: published. Published: 2026-06-24. Updated: 2026-11-10.

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

netfilter: nft_ct: fix missing expect put in obj eval

nft_ct_expect_obj_eval() allocates an expectation and may call
nf_ct_expect_related(), but never drops its local reference.

Add nf_ct_expect_put(exp) before return to balance allocation.

## 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/19f94b6fee75b3ef7fbc06f3745b9a771a8a19a4
- 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/1dced0725e2fae3ac3416274db20a7ff5a46931d
- 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/26ab32ec73941871c97562ee1f39587950dc3b68
- 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/2aef1b13d5c0285f340512c6c07eb858fd018fd8
- 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/7b96242ceedfe249f158419f3254bcee04173ffe
- 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/84c422cea5a45fe56be839f25880f21fd33940cd
- 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/cdb9a25dd3416d427e8b2753210f8baf44207577
- 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/ecca618e1e339494911090474ed87742c0f73976

## Affected products and versions

- Linux / Linux: ≥ 857b46027d6f91150797295752581b7155b9d0e1; < cdb9a25dd3416d427e8b2753210f8baf44207577 (affected, git); ≥ 857b46027d6f91150797295752581b7155b9d0e1; < 26ab32ec73941871c97562ee1f39587950dc3b68 (affected, git); ≥ 857b46027d6f91150797295752581b7155b9d0e1; < 7b96242ceedfe249f158419f3254bcee04173ffe (affected, git); ≥ 857b46027d6f91150797295752581b7155b9d0e1; < ecca618e1e339494911090474ed87742c0f73976 (affected, git); ≥ 857b46027d6f91150797295752581b7155b9d0e1; < 2aef1b13d5c0285f340512c6c07eb858fd018fd8 (affected, git); ≥ 857b46027d6f91150797295752581b7155b9d0e1; < 1dced0725e2fae3ac3416274db20a7ff5a46931d (affected, git); ≥ 857b46027d6f91150797295752581b7155b9d0e1; < 84c422cea5a45fe56be839f25880f21fd33940cd (affected, git); ≥ 857b46027d6f91150797295752581b7155b9d0e1; < 19f94b6fee75b3ef7fbc06f3745b9a771a8a19a4 (affected, git). Source: CNA: Linux
- Linux / Linux: 5.3 (affected); ≥ 0; < 5.3 (unaffected, semver); ≥ 5.10.258; ≤ 5.10.* (unaffected, semver); ≥ 5.15.209; ≤ 5.15.* (unaffected, semver); ≥ 6.1.175; ≤ 6.1.* (unaffected, semver); ≥ 6.6.141; ≤ 6.6.* (unaffected, semver); ≥ 6.12.91; ≤ 6.12.* (unaffected, semver); ≥ 6.18.33; ≤ 6.18.* (unaffected, semver); ≥ 7.0.10; ≤ 7.0.* (unaffected, semver); ≥ 7.1; ≤ * (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": "5.10.258",
            "versionStartIncluding": "5.3",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "5.15.209",
            "versionStartIncluding": "5.11",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.1.175",
            "versionStartIncluding": "5.16",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.6.141",
            "versionStartIncluding": "6.2",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.12.91",
            "versionStartIncluding": "6.7",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.18.33",
            "versionStartIncluding": "6.13",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "7.0.10",
            "versionStartIncluding": "6.19",
            "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
          }
        ],
        "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 2.96%

- 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/cdb9a25dd3416d427e8b2753210f8baf44207577 (CNA: Linux)

- https://git.kernel.org/stable/c/26ab32ec73941871c97562ee1f39587950dc3b68 (CNA: Linux)

- https://git.kernel.org/stable/c/7b96242ceedfe249f158419f3254bcee04173ffe (CNA: Linux)

- https://git.kernel.org/stable/c/ecca618e1e339494911090474ed87742c0f73976 (CNA: Linux)

- https://git.kernel.org/stable/c/2aef1b13d5c0285f340512c6c07eb858fd018fd8 (CNA: Linux)

- https://git.kernel.org/stable/c/1dced0725e2fae3ac3416274db20a7ff5a46931d (CNA: Linux)

- https://git.kernel.org/stable/c/84c422cea5a45fe56be839f25880f21fd33940cd (CNA: Linux)

- https://git.kernel.org/stable/c/19f94b6fee75b3ef7fbc06f3745b9a771a8a19a4 (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/19f94b6fee75b3ef7fbc06f3745b9a771a8a19a4 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/1dced0725e2fae3ac3416274db20a7ff5a46931d (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/26ab32ec73941871c97562ee1f39587950dc3b68 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/2aef1b13d5c0285f340512c6c07eb858fd018fd8 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/7b96242ceedfe249f158419f3254bcee04173ffe (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/84c422cea5a45fe56be839f25880f21fd33940cd (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/cdb9a25dd3416d427e8b2753210f8baf44207577 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

- https://git.kernel.org/stable/c/ecca618e1e339494911090474ed87742c0f73976 (416baaa9-dc9f-4396-8d5f-8c081fb06d67; Patch)

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

- 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-2026-52970; retrieved 2026-11-10; source updated 2026-11-10

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52970; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-52970; retrieved 2026-11-10; source updated Not reported

Revision: 36866d717a5aec18080932109e2e4fd04c5356528343883e9245166d9d5a41c2

Canonical: https://y2.dev/cve/CVE-2026-52970

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