SECUFOCUSNOW
Home›CVE index›CVE-2025-40183
Review reviewHigh

CVE-2025-40183

Linux

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix metadata_dst leak __bpf_redirect_neigh_v{4,6} Cilium has a BPF egress gateway feature which forces outgoing K8s Pod traffic to pass through dedicated egress gateways which then SNAT the traffic in order to interact with stable IPs outside the cluster. The traffic is directed to the gateway via vxlan tunnel in collect md mode. A recent BPF change utilized the bpf_redirect_neigh() helper to forward packets after the arrival and decap on vxlan, which turned out over time that the kmalloc-256 slab usage in kernel was e...

CVSS
7.5
EPSS
0.57%
44.1% percentile
CISA KEV
Not listed
Published
2025.11.13
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.57%
Technical severityCVSS 7.5

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix metadata_dst leak __bpf_redirect_neigh_v{4,6} Cilium has a BPF egress gateway feature which forces outgoing K8s Pod traffic to pass through dedicated egress gateways which then SNAT the traffic in order to interact with stable IPs outside the cluster. The traffic is directed to the gateway via vxlan tunnel in collect md mode. A recent BPF change utilized the bpf_redirect_neigh() helper to forward packets after the arrival and decap on vxlan, which turned out over time that the kmalloc-256 slab usage in kernel was e...

Affected product and versions

Product
Linux
Affected versions
>= b4ab31414970a7a03a5d55d75083f2c101a30592 < 3fba965a9aac0fa3cbd8138436a37af9ab466d79, >= b4ab31414970a7a03a5d55d75083f2c101a30592 < 057764172fcc6ee2ccb6c41351a55a9f054dc8fd, >= b4ab31414970a7a03a5d55d75083f2c101a30592 < 2e67c2037382abb56497bb9d7b7e10be04eb5598, >= b4ab31414970a7a03a5d55d75083f2c101a30592 < b6bfe44b6dbb14a31d86c475cdc9c7689534fb09, >= b4ab31414970a7a03a5d55d75083f2c101a30592 < f36a305d30f557306d87c787ddffe094ac5dac89, >= b4ab31414970a7a03a5d55d75083f2c101a30592 < 7404ce888a45eb7da0508b7cbbe6f2e95302eeb8, >= b4ab31414970a7a03a5d55d75083f2c101a30592 < 23f3770e1a53e6c7a553135011f547209e141e72, >= 5.10
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
Not available
CVE-2025-40183 — Linux | SECUFOCUS NOW