CVE-2025-40183bpf: Fix metadata_dst leak __bpf_redirect_neigh_v{4,6}
- 7.5HighCVSS base score
- 0.63%Exploitation in 30 daysEPSS · top 49% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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 ever-increasing. The issue was that vxlan allocates the metadata_dst object and attaches it through a fake dst entry to the skb. The latter was never released though given bpf_redirect_neigh() was merely setting the new dst entry via skb_dst_set() without dropping an existing one first.
Timeline
ID reserved
By Linux
- 7 months later
· 7 months later
Published
- 11 months later
· 11 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Deferred | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.63% · top 49% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected b4ab31414970a7a03a5d55d75083f2c101a30592 – < 3fba965a9aac0fa3cbd8138436a37af9ab466d79
- affected b4ab31414970a7a03a5d55d75083f2c101a30592 – < 057764172fcc6ee2ccb6c41351a55a9f054dc8fd
- affected b4ab31414970a7a03a5d55d75083f2c101a30592 – < 2e67c2037382abb56497bb9d7b7e10be04eb5598
- affected b4ab31414970a7a03a5d55d75083f2c101a30592 – < b6bfe44b6dbb14a31d86c475cdc9c7689534fb09
- affected b4ab31414970a7a03a5d55d75083f2c101a30592 – < f36a305d30f557306d87c787ddffe094ac5dac89
- affected b4ab31414970a7a03a5d55d75083f2c101a30592 – < 7404ce888a45eb7da0508b7cbbe6f2e95302eeb8
- affected b4ab31414970a7a03a5d55d75083f2c101a30592 – < 23f3770e1a53e6c7a553135011f547209e141e72
- affected 5.10
- unaffected < 5.10
- unaffected 5.10.246 – ≤ 5.10.*
- unaffected 5.15.195 – ≤ 5.15.*
- unaffected 6.1.157 – ≤ 6.1.*
- unaffected 6.6.113 – ≤ 6.6.*
- unaffected 6.12.54 – ≤ 6.12.*
- unaffected 6.17.4 – ≤ 6.17.*
- unaffected 6.18 – ≤ *
References
References7
- https://git.kernel.org/stable/c/3fba965a9aac0fa3cbd8138436a37af9ab466d79 (opens in a new tab)
- https://git.kernel.org/stable/c/057764172fcc6ee2ccb6c41351a55a9f054dc8fd (opens in a new tab)
- https://git.kernel.org/stable/c/2e67c2037382abb56497bb9d7b7e10be04eb5598 (opens in a new tab)
- https://git.kernel.org/stable/c/b6bfe44b6dbb14a31d86c475cdc9c7689534fb09 (opens in a new tab)
- https://git.kernel.org/stable/c/f36a305d30f557306d87c787ddffe094ac5dac89 (opens in a new tab)
- https://git.kernel.org/stable/c/7404ce888a45eb7da0508b7cbbe6f2e95302eeb8 (opens in a new tab)
- https://git.kernel.org/stable/c/23f3770e1a53e6c7a553135011f547209e141e72 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-150391 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-40183)Record last updated .