CVE-2025-40183: linux
Vulnerability summary
CVE-2025-40183 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.62% chance of exploitation in the next 30 days, higher than 48.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 46 · Related 44Timeline
- 12-11-2025PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.62%
Chance of exploitation in the next 30 days
Percentile
49%
Versus all other CVEs
30-day change
+0.04 pp
From 0.58% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu141 products
- linux< 5.15.0-170.180 | < 6.8.0-106.106 | < 6.17.0-14.14
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1100.107 | < 6.8.0-1050.53 | < 6.17.0-1007.7
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linux< 6.1.158-1 | < 6.12.57-1 | < 6.17.6-1
Linux1 product
- linux≥ b4ab31414970a7a03a5d55d75083f2c101a30592, < 3fba965a9aac0fa3cbd8138436a37af9ab466d79 | ≥ b4ab31414970a7a03a5d55d75083f2c101a30592, < 057764172fcc6ee2ccb6c41351a55a9f054dc8fd | ≥ b4ab31414970a7a03a5d55d75083f2c101a30592, < 2e67c2037382abb56497bb9d7b7e10be04eb5598 | ≥ b4ab31414970a7a03a5d55d75083f2c101a30592, < b6bfe44b6dbb14a31d86c475cdc9c7689534fb09 | ≥ b4ab31414970a7a03a5d55d75083f2c101a30592, < f36a305d30f557306d87c787ddffe094ac5dac89 | ≥ b4ab31414970a7a03a5d55d75083f2c101a30592, < 7404ce888a45eb7da0508b7cbbe6f2e95302eeb8 | ≥ b4ab31414970a7a03a5d55d75083f2c101a30592, < 23f3770e1a53e6c7a553135011f547209e141e72 | 5.10
3 vendors · 143 products
