Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Linux Linux — net: clear the dst when changing skb protocol
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0016 5.7 —
AFFECTED
Product Versions Fixed
Linux 6578171a7ff0c31dc73258f93da7407510abf085 – —
Linux 4.8 – 5.15.209
TIMELINE
Apr 16 Reserved by Linux
Jul 4 Published (CNA: Linux)
Jul 30 RESCORED — CVE-2025-38192 (Linux). CVSS 7.8 → 5.5 (NVD).
Description
In the Linux kernel, the following vulnerability has been resolved:
net: clear the dst when changing skb protocol
A not-so-careful NAT46 BPF program can crash the kernel
if it indiscriminately flips ingress packets from v4 to v6:
BUG: kernel NULL pointer dereference, address: 0000000000000000
ip6_rcv_core (net/ipv6/ip6_input.c:190:20)
ipv6_rcv (net/ipv6/ip6_input.c:306:8)
process_backlog (net/core/dev.c:6186:4)
napi_poll (net/core/dev.c:6906:9)
net_rx_action (net/core/dev.c:7028:13)
do_softirq (kernel/softirq.c:462:3)
netif_rx (net/core/dev.c:5326:3)
dev_loopback_xmit (net/core/dev.c:4015:2)
ip_mc_finish_output (net/ipv4/ip_output.c:363:8)
NF_HOOK (./include/linux/netfilter.h:314:9)
ip_mc_output (net/ipv4/ip_output.c:400:5)
dst_output (./include/net/dst.h:459:9)
ip_local_out (net/ipv4/ip_output.c:130:9)
ip_send_skb (net/ipv4/ip_output.c:1496:8)
udp_send_skb (net/ipv4/udp.c:1040:8)
udp_sendmsg (net/ipv4/udp.c:1328:10)
The output interface has a 4->6 program attached at ingress.
We try to loop the multicast skb back to the sending socket.
Ingress BPF runs as part of netif_rx(), pushes a valid v6 hdr
and changes skb->protocol to v6. We enter ip6_rcv_core which
tries to use skb_dst(). But the dst is still an IPv4 one left
after IPv4 mcast output.
Clear the dst in all BPF helpers which change the protocol.
Try to preserve metadata dsts, those may carry non-routing
metadata.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| April 16, 2025 | Reserved | Reserved by Linux |
| July 4, 2025 | Published | Published (CNA: Linux) |
| July 30, 2026 | RESCORED | RESCORED — CVE-2025-38192 (Linux). CVSS 7.8 → 5.5 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 6578171a7ff0c31dc73258f93da7407510abf085 | — |
| Linux | Linux | — | 4.8 | 5.15.209 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2025-38192 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.