In the Linux kernel, the following vulnerability has been resolved:
net/tunnel: wait until all sk_user_data reader finish before releasing the sock
There is a race condition in vxlan that when deleting a vxlan device
during receiving packets, there is a possibility that the sock is
released after getting vxlan_sock vs from sk_user_data. Then in
later vxlan_ecn_decapsulate(), vxlan_get_sk_family() we will got
NULL pointer dereference. e.g.
#0 [ffffa25ec6978a38] machine_kexec at ffffffff8c669757
#1 [ffffa25ec6978a90] __crash_kexec at ffffffff8c7c0a4d
#2 [ffffa25ec6978b58] crash_kexec at ffffffff8c7c1c48
#3 [ffffa25ec6978b60] oops_end at ffffffff8c627f2b
#4 [ffffa25ec6978b80] page_fault_oops at ffffffff8c678fcb
#5 [ffffa25ec6978bd8] exc_page_fault at ffffffff8d109542
#6 [ffffa25ec6978c00] asm_exc_page_fault at ffffffff8d200b62
[exception RIP: vxlan_ecn_decapsulate+0x3b]
RIP: ffffffffc1014e7b RSP: ffffa25ec6978cb0 RFLAGS: 00010246
RAX: 0000000000000008 RBX: ffff8aa000888000 RCX: 0000000000000000
RDX: 000000000000000e RSI: ffff8a9fc7ab803e RDI: ffff8a9fd1168700
RBP: ffff8a9fc7ab803e R8: 0000000000700000 R9: 00000000000010ae
R10: ffff8a9fcb748980 R11: 0000000000000000 R12: ffff8a9fd1168700
R13: ffff8aa000888000 R14: 00000000002a0000 R15: 00000000000010ae
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#7 [ffffa25ec6978ce8] vxlan_rcv at ffffffffc10189cd [vxlan]
#8 [ffffa25ec6978d90] udp_queue_rcv_one_skb at ffffffff8cfb6507
#9 [ffffa25ec6978dc0] udp_unicast_rcv_skb at ffffffff8cfb6e45
#10 [ffffa25ec6978dc8] __udp4_lib_rcv at ffffffff8cfb8807
#11 [ffffa25ec6978e20] ip_protocol_deliver_rcu at ffffffff8cf76951
#12 [ffffa25ec6978e48] ip_local_deliver at ffffffff8cf76bde
#13 [ffffa25ec6978ea0] __netif_receive_skb_one_core at ffffffff8cecde9b
#14 [ffffa25ec6978ec8] process_backlog at ffffffff8cece139
#15 [ffffa25ec6978f00] __napi_poll at ffffffff8ceced1a
#16 [ffffa25ec6978f28] net_rx_action at ffffffff8cecf1f3
#17 [ffffa25ec6978fa0] __softirqentry_text_start at ffffffff8d4000ca
#18 [ffffa25ec6978ff0] do_softirq at ffffffff8c6fbdc3
Reproducer: https://github.com/Mellanox/ovs-tests/blob/master/test-ovs-vxlan-remove-tunnel-during-traffic.sh
Fix this by waiting for all sk_user_data reader to finish before
releasing the sock.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it