CASCACascade Atlas

Evidence dossier

CVE-2021-22555

Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE

69.2–93.5Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space

State
PUBLISHED
Published
Jul 7, 2021
Updated
Dec 30, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

FIRST EPSS78.68%

2026-07-18 · v2026.06.15 · percentile 99.5%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

Googleoriginal assertion
container

Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE

CISA KEVoriginal assertion
observed_exploitation

Linux Kernel Heap Out-of-Bounds Write Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.786840000000; percentile 0.995440000000

Applicability

Cited product scope

Trace impact →
n/aLinux Kernel
[{"status": "affected", "version": "2.6.19-rc1", "lessThan": "unspecified", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:netapp:solidfire_baseboard_management_controller:*:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:h:netapp:aff_500f:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:aff_a250:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:aff_a400:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:c250:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:c400:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:fas_8300:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:fas_8700:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h610c:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h610s:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h615c:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:brocade:fabric_operating_system:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*; start including 2.6.19; end excluding 4.4.267supported
Unknown vendorUnknown product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*; start including 4.5; end excluding 4.9.267supported
Unknown vendorUnknown product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*; start including 4.10; end excluding 4.14.231supported
Unknown vendorUnknown product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*; start including 4.15; end excluding 4.19.188supported
Unknown vendorUnknown product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*; start including 4.20; end excluding 5.4.113supported
Unknown vendorUnknown product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*; start including 5.5; end excluding 5.10.31supported
Unknown vendorUnknown product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*; start including 5.11; end excluding 5.12supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:aff_500f_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:aff_a250_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:aff_a400_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:c250_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:c400_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:fas_8300_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:fas_8700_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h610c_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h610s_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h615c_firmware:-:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:*supported

Assessments

CVSS by origin

7.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6
nvd@nist.govCVSS 2.0 · role PrimaryAV:L/AC:L/Au:N/C:P/I:P/A:P
8.3
cve-coordination@google.comCVSS 3.1 · role SecondaryCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
8.3
GoogleCVSS 3.1 · role unknownCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.