# CVE-2026-64413: netfilter: ebtables: zero chainstack array

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

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

netfilter: ebtables: zero chainstack array

sashiko reports:
 looking at ebtables table
 translation, could a sparse cpu_possible_mask lead to an uninitialized pointer
 free?

 If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible,
 but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at
 CPU 2, the cleanup loop will blindly decrement and call vfree() on
 newinfo->chainstack[1].

Not a real-world bug, such allocation isn't expected to fail
in the first place.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 2ade612967e2cdfb9290ebcb773f302c82f311fa (affected, git); ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 42bef500d07b5769d916e9122a3e3fa3fd2245ef (affected, git); ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < fc7f105451044501a50cfd530cfa3b472c54acbc (affected, git); ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 9e6c5169db423e51dcc66a73fd15409c0d38e088 (affected, git); ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 29bf41a9b59aff9f6197df58641a00037d567ca8 (affected, git); ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 9f74d28e903fa4fdf82f870d0aeadddc8196e41c (affected, git); ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < 5ee856e4208acafaaaf7b84824d39b78c21345d6 (affected, git); ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2; < cbfe53599eebffd188938ab6774cc41794f6f9d5 (affected, git). Source: CNA: Linux
- Linux / Linux: 2.6.12 (affected); ≥ 0; < 2.6.12 (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); ≥ 6.18.39; ≤ 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

## Severity and prioritization

- CVSS 3.1: 7 (high); CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H; source: CNA: Linux

- CISA KEV: No listing in collected sources

- EPSS: 0.13% as of 2026-11-09; percentile 2.45%

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

- Weaknesses: CWE-457

## Exploit evidence

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

## References

- https://git.kernel.org/stable/c/2ade612967e2cdfb9290ebcb773f302c82f311fa (CNA: Linux)

- https://git.kernel.org/stable/c/42bef500d07b5769d916e9122a3e3fa3fd2245ef (CNA: Linux)

- https://git.kernel.org/stable/c/fc7f105451044501a50cfd530cfa3b472c54acbc (CNA: Linux)

- https://git.kernel.org/stable/c/9e6c5169db423e51dcc66a73fd15409c0d38e088 (CNA: Linux)

- https://git.kernel.org/stable/c/29bf41a9b59aff9f6197df58641a00037d567ca8 (CNA: Linux)

- https://git.kernel.org/stable/c/9f74d28e903fa4fdf82f870d0aeadddc8196e41c (CNA: Linux)

- https://git.kernel.org/stable/c/5ee856e4208acafaaaf7b84824d39b78c21345d6 (CNA: Linux)

- https://git.kernel.org/stable/c/cbfe53599eebffd188938ab6774cc41794f6f9d5 (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)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-64413; retrieved 2026-11-10; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-64413; retrieved 2026-11-10; source updated Not reported

Revision: 5602c54f020e3b675a0561c793fae426257b0ac564af215f935d9f408f33c07c

Canonical: https://y2.dev/cve/CVE-2026-64413

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