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: gso: fix ownership in __udp_gso_segment
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0023 13.7 —
AFFECTED
Product Versions Fixed
Linux ad405857b174ed31a97982bb129c320d03321cf5 – —
Linux 4.18 – 5.4.291
TIMELINE
Dec 29 Reserved by Linux
Apr 1 Published (CNA: Linux)
Jul 30 RESCORED — CVE-2025-21926 (Linux). CVSS 7.8 → 5.5 (NVD).
Description
In the Linux kernel, the following vulnerability has been resolved:
net: gso: fix ownership in __udp_gso_segment
In __udp_gso_segment the skb destructor is removed before segmenting the
skb but the socket reference is kept as-is. This is an issue if the
original skb is later orphaned as we can hit the following bug:
kernel BUG at ./include/linux/skbuff.h:3312! (skb_orphan)
RIP: 0010:ip_rcv_core+0x8b2/0xca0
Call Trace:
ip_rcv+0xab/0x6e0
__netif_receive_skb_one_core+0x168/0x1b0
process_backlog+0x384/0x1100
__napi_poll.constprop.0+0xa1/0x370
net_rx_action+0x925/0xe50
The above can happen following a sequence of events when using
OpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an
OVS_ACTION_ATTR_OUTPUT action:
1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb
goes through queue_gso_packets and then __udp_gso_segment, where its
destructor is removed.
2. The segments' data are copied and sent to userspace.
3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the
same original skb is sent to its path.
4. If it later hits skb_orphan, we hit the bug.
Fix this by also removing the reference to the socket in
__udp_gso_segment.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| December 29, 2024 | Reserved | Reserved by Linux |
| April 1, 2025 | Published | Published (CNA: Linux) |
| July 30, 2026 | RESCORED | RESCORED — CVE-2025-21926 (Linux). CVSS 7.8 → 5.5 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | ad405857b174ed31a97982bb129c320d03321cf5 | — |
| Linux | Linux | — | 4.18 | 5.4.291 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2025-21926 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.